LIGHT DUTY TRUCK WIRING DIAGRAM BOOKLET ST

Transcription

1 1988 LIGHT DUTY TRUCK WIRING DIAGRAM BOOKLET ST

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3 1 WIRING DIAGRAMS 2 WIRING DIAGRAMS DESCRIPTION All diagrams in this manual are based n the latest prduct infrmatin at the time f publicatin apprval. The right is reserved t make changes at any time withut ntice. 9A 0.5 BRN SUBJECT PAGE Descriptin... 2 Tracing Circuits... 2 Basic Electric Circuits... 2 Circuit Diagnsis... 6 Abbreviatin List Diagnstic Tls... 9 Wire Size Cnversin Table On-Vehicle Service Circuit Maintenance and Repair...11 Weather Pack Cnnectrs Metri-Pack Cnnectrs...12 Wiring Repair...14 Special Tls...15 WIRE CIRCUIT NUMBER WIRE SIZE IN SQ. MM. I COLOR OF WIRE INSULATION BLK...Black PPL...Purple BRN...Brwn TR...Tracer CHK...Check YEL...Yellw CR...Crss I I...Parallel G RN...Green W HT...White N A T...Natural BLU...Blue S G L...Single STR...Stripe ORN...Orange PNK...Pink GR...Gray DK...Dark Figure 1 Wire Cding F VEHICLE SECTION C/K Mdels...A-1 G Van... B-1 S/T Mdels...C-1 R/V Mdels...D-1 P Chassis... E-1 M Van... F-1 The diagrams are t be traced frm the surce f electricity (the battery psitive pst) t grund. The grund may be a chassis grund n a certain cmpnent (such as an alternatr r a starter), r a wire frm a cmpnent t a chassis r frame grund (such as used n the electrnic cntrl mdule and instrument panel). All grunds are cnnected t the negative battery pst thrugh bdy and/r engine grund wires and straps. Many times the surce f the electricity is shwn as the ignitin switch r the fuse blck. This is dne t eliminate the cnfusin that wuld ccur if the entire pwer distributin was shwn in each circuit. Fr a detailed utline f the pwer t the ignitin switch r the fuse blck, refer t the pwer distributin circuit. The grund prtin f the circuit (usually circuit 150 r 151) may be shwn entirely, r it may refer t the grund distributin circuit in rder t avid cnfusin f listing all the grunds in ne splice n a single page. Fr ease f diagnsis, all splices and grunds are identified by number, and all the wires in a cmmn splice r grund are identified by circuit number, size (in mm) and clr. Each cmpnent r circuit cmmn t s spliced wire is called ut by the page number f that circuit. This will help identify and diagnse multiple electrical prblems that culd ccur in a truck. All cnnectrs are shwn with their part numbers t save time when rdering these parts. Switches are shwn in their at rest psitins, unless therwise marked. TRACING CIRCUITS Figures 1 thrugh 3 are examples f hw the wiring diagrams are laid ut, and will be referred t, thrughut this descriptin. In rder t trace a circuit n these diagrams, start frm the surce, the battery. In figure 2, the battery psitive circuit is a 19.0 mm black wire. This wire runs frm the battery t the starter mtr, and supplies pwer t the starter mtr pst. Once yu have determined the surce f pwer t yur cmpnent, frm the Pwer Distributin Circuit (figure 2), then refer t the individual circuit yu are wrking n fr mre detail abut that circuit. (Figure 3 shws the starting circuit). In figure 3, the starter mtr circuit is shwn. This circuit shw s the b a tte ry feed cm ing frm the Pwer Distributin page. The cable cmes frm the battery t the starter psitive pst. At the starter pst, ther circuits such as the generatr, ignitin switch, and electrnic cntrl mdule are fed. When the ignitin switch is in the start psitin, pwer flws frm circuit #2 thrugh the switch, t circuit #6. C ircuit #6 ges thrugh the clutch switch with an autmatic transmissin. At the clutch switch the circuit is pened, unless the clutch is depressed. At the slenid the current flwing frm circuit #6, clses the slenid, allwing current t flw frm the battery at circuit #1 t the starter mtr. The current flwing t the starter mtr, causes the starter mtr t spin. BASIC ELECTRICAL CIRCUITS An electrical circuit starts frm a supply f electricity back t a lad and then cnducts the electricity back t the supply f electricity. There shuld be a device t pen and clse the circuit, and a prtective device t pen the circuit in case t much current is drawn int the circuit by an verlad cnditin. Electrical circuits can be set up as series circuits, parallel circuits r series/parallel circuits. The circuits in trucks are usually parallel circuits.

4 WIRING DIAGRAMS 3 WIRING DIAGRAMS 4 - IH M /N V IS 'C C - N U 9 M 0 S - s c - 1XM/NV1 9 -ce - - X18/WW B 6C - Xlfl/XNd B'-6C ' < -Q 9 B 0 S Q3UO'C-Z - - Xlfl/WU 8 6E - m a i s s i n j s t u s s 'Q a (CK O O K M i J L -L i.1.1.a p 2 : f t k l 3 5 F r J j - Xlfl/XNd 8 6C <k a Ui E iu (9 «Xlfl/XNd 8 6C - p fgl jl l ml i i ks mr M mu dm t a IDEOn E B h e m m r H I) n si BID W 3 i i m I 1 t u< t _L T < TO ECM t - 1 «0 9 9 s n s 9 / - Tdd s-9 00 * isnu S9 < a. SjjO nx iu 2 «F F Figure 2 Pwer Distributin Figure 3 Starter System

5 WIRING DIAGRAMS 5 WIRING DIAGRAMS 6 3 path. Fr example the switch cntrlling the headlights is at the pwer end f the circuit while the dr switch cntrlling the dmelight cmpletes the grund path. Relays are remtely cntrlled switches. They are used in high current circuits and in circuits cntrlled by sensrs. Relays are designed s that a small current circuit will be able t cntrl a large current circuit. 1. Battery 2. Parallel Circuit 3. Lad 4. Switch 5. Series Circuit Figure 4 Basic Circuits B SERIES CIRCUITS (Figure 4 and 5) In a series circuit, the electrical devices are cnnected tgether t frm ne current path t and frm the pwer supply. In a series circuit the same current flws thrugh all f the devices. PARALLEL CIRCUITS (Figure 5) In a parallel circuit, the electrical devices are cnected t frm mre than ne current path t and frm the pwer supply. In a parallel circuit the supply vltage is the same in each current path. SERIES/PARALLEL CIRCUIT (Figure 5) A series/parallel circuit cnsists f a single current path circuit and a circuit with mre than ne current path t and frm the vltage supply. CIRCUIT COMPONENTS (Figure 6) The usual circuit path starts at the pwer supply which is the battery/generatr system. Next in the circuits is the circuit prtectin cmpnent which can be a fusible link, a fuse, r a circuit breaker. Then the circuit ges t the circuit cntrller which can be a switch r a relay. Frm the circuit cntrller the circuit ges int the circuit lad. The circuit lad can be ne light r many lights in parallel, an electric mtr r a slenid. After the electricity has passed thrugh the lad it must return t the pwer supply via the grund path. The grund path can be a wire in the harness r it culd be thrugh the lad husing int the bdy r frame, thus returning the electricity t the pwer supply. The bdy and frame are cnnected by flexible grund straps. FUSIBLE LINK Figure 5 Series/Parallel Circuits A fusible link is a sectin f wire that is usually fur gage sizes smaller than the circuit it prtects. A special insulatin is used that swells when heated by the wire. Fusible links are usually fund in the engine cmpartment harnesses. The functin f the fusible link is t melt pen when an verlad ccurs, thus preventing any damage t the circuit. Figure 6 Circuit Cmpnents FUSES (Figure 6) The mst cmmn prtectr in the vehicle circuit is a fuse. A fuse cnsists f a fine wire r strip f metal inside a glass tube r plastic husing. The strip melts and interrupts the flw f current in the circuit when there is an verlad caused by an unwanted shrt r grund. The fuse is designed t melt befre the wiring r electrical cmpnents in a circuit can be damaged. Naturally, the cause must be lcated and crrected befre the fuse is replaced r the new fuse will als blw. Since different circuits handle different amunts f current, fuses f varius ratings are used. Fuses are rated in amperes. Be sure t replace a blwn fuse with a fuse f the cnnecting rating. CIRCUIT CONTROLLERS (Figure 7) C ircu it c ntrlle rs cnsist f sw itches r relays. Switches are usually perated by a mechanical means such as a hand r lever. Switches are usually at the beginning f a circuit but can be used t cntrl a grund CIRCUIT BREAKERS (Figure 7) Circuit breakers are anther frm f circuit prtectr. There are tw types f circuit breakers; autmatic reset and remte reset. The autmatic reset breaker pens when excess current heats a bimetallic strip, causing the strip t bend and pen a set f cntacts. Then the strip cls and clses the cntacts. S the circuit breaker pens and clses until the excess current cnditin is crrected r the circuit is discnnected frm the pwer supply. The remte reset circuit breaker has a heating wire wund arund the bimetallic strip. When an excess current happens, the strip heats, bends, and pens the cntacts. Then a small current flws thrugh the heating wire, keeping the strip ht and the cntacts pen. This type f breaker will stay pen until either the pwer supply is discnnected frm the circuit r the breaker is remved frm the circuit. Then the breaker can cl and reset. CIRCUIT LOADS (Figure 7) Circuit lads are the cmpnents that use mst f the energy in circuit. The energy cnverts t mtin, light, r heat. Lights, mtrs, and engine heaters are the mst cmmn lads in circuits. CIRCUIT DIAGNOSIS A clear understanding f the circuit and a wiring diagram are needed fr effective diagnsis. Use a lgical sequence f testing t find the truble. Use the diagnstic tls. After the truble is fixed, make sure the circuit wrks crrectly. CIRCUIT MALFUNCTIONS There are three electrical cnditins that can cause a nnwrking circuit; an Open Circuit, a Shrt C ircuit, r a Grunded Circuit. OPEN CIRCUIT (Figure 8) An pen circuit ccurs whenever there is a break in the circuit. The break can be crrsin at the cnnectr, a wire brken ff in a device, r a wire that burned pen frm t much current. SHORT CIRCUIT (Figure 9) A shrt circuit happens when the current bypasses part f the nrmal circuit. This bypassing is usually caused by wires tuching, salt water in r n a device such as a switch r a cnnectr r slder melting and bridging cnductrs in a device.

6 WIRING DIAGRAMS 7 WIRING DIAGRAMS 8 The fllwing is a list f abbreviatins used in the wiring diagrams. The abbreviatins have been develped in such a way that their meaning shuld be clear. Use this page as a reference t determine the meaning f an abbreviatin if necessary. A Ampere A/C Air Cnditiner ACC Accessry A.I.R. Air Injectin Reactin AIR/COND Air Cnditiner ALDL Assembly Line Diagnstic Link ALT Alternatr AMP Ampere ANTI Anticipate ASM Assembly ASS Y Assembly AUD Audi AUTO Autmatic AUX Auxiliary BAT Battery BATT Battery BI-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bttm ABBREVIATION LIST ED CIRCUIT (Figure 10) A grund circuit is like a shrt circuit but the current flws directly int a grund circuit that is nt part f the riginal circuit. This may be caused by a wire rubbing against the frame r bdy. Smetimes a wire will break and fall against metal that is cnnected electrically t the grund side f the pwer supply. A grunded circuit may als be caused by depsits f il, dirt and misture arund cnnectins r terminals, which prvide a gd path t grund. BRK Brake BRN Brwn BU Backup BUZZ Buzzer CIR/BRK Circuit Breaker CIRC Circuit CLSTR Cluster CNTL Cntrl COMP Cmpartment COMP Cmpressr CONN Cnnectr CONV Cnvenience CTS Y Curtesy CYL Cylinder DK Dark DIAG Diagnstic DIM Dimmer DIR Directinal DISC Discrete DIST Distributr DIV Diverter DM Dme DR Dr ECM Electrnic Cntrl Mdule EFE Early Fuel Evapratin EGR Exhaust Gas Recirculatin ELEC Electric ELEC Electrnic CNTRL Cntrl MOD Mdule ENG Engine EPR Exhaust Pressure Regulatr ESC Electrnic Spark Cntrl EST Electrnic Spark Timing EVRV Electrnic Vacuum Regulatr Valve EXC Except F-PUMP Fuel Pump FLASH Flasher FRT Frnt 4WD Fur Wheel Drive GEN Generatr GRA Gray GRD Grund GRN Green HAND Handling HAZ Hazard HD Heavy Duty HD LP Headlamp HEI High Energy Ignitin HI High HTR Heater IAC Idler Air Cntrl IGN Ignitin ILLUM Illuminatin l/p Instrument Panel INC Increased IND Indicatr INJ Injectr INST PNL Instrument Panel INTER Interir LD Light Duty LH Left Hand LO Lw LP Lamp LPS Lamps LT Light LTR Lighter M Mtr MAN Manual MAP Manifld Abslute Pressure MAX Maximum MED Medium MRKR Marker MULT Multiple NAT Natural NEUT Neutral NO Nrmally Open NC Nrmally Clsed ORN Orange PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PWR Pwer RCVR Receiver REF Reference RESIST Resistance RH Right Hand RPO Regular Prductin Optin SEN Senser SEND Sender SIG Signal SIL Silver SKT Scket SOL Slenid SPEEDO Speedmeter STR Stripe SW Switch TACH Tachmeter TBI Thrttle Bdy Injectin TCC Trque Cnverter Clutch TEMP Temperature T/L Tail Lamp TRANS Transmissin TYP Typical V Vlt VAC Vacuum VLV Valve VSS Vehicle Speed Sensr W/ With W/O Withut W/S Windshield W WASHER Windw Washer WDO Windw WHT White WRG Wiring YEL Yellw

7 WIRING DIAGRAMS 9 WIRING DIAGRAMS 10 DIAGNOSTIC TOOLS VOLTS VOLTMETER SCALE: 0 V lts th r u g h 15 V lts A = 3 Vlts B = 7 Vlts C = 13 Vlts UNPOWEREO TEST LIGHT (Figure 12) This tl cnsists f a 12 vlt light with leads. The ends f the leads usually have alligatr clamps, but varius kinds f prbes, terminal spades, and special cnnectrs are used als. The unpwered test light is used n an pen circuit. One lead f the test light is grunded and the ther lead is mved arund the circuit t find the pen. Depending n the physical layut f the circuit, smetimes it will be easier t start at the pwer supply and ther times it is easier t start at the circuit lad r grund circuit. POWERED TEST LIGHT (Figure 11) This light is a pencil shaped unit with a self cntained battery, a 1.5 vlt light bulb, a sharp prbe and a grund lead fitted with an alligatr clip. This test light is used mainly fr testing cmpnents that are discnnected frm the vehicle pwer supply. The pwer test light is als useful fr testing suspected high resistance pints in a circuit such as cnnectrs and grund circuits that are crrded r lse. JUMPER The jumper is usually a lng wire with alligatr clamps. A versin f the jumper has a fuse hlder in it with a 10 Amp fuse. This will prevent damaging the circuit if the jumper is cnnected in the wrng way. The jumper is used t lcate pens in a circuit. One end f the jumper is attached t a pwer surce and then the ther end is attached t the lad in the circuit, i.e.; light, mtr. If the lad wrks, try jumping t circuit pints that are prgressively clser t the pwer supply. When the circuit lad stps wrking, the pen has been lcated. The jumper is als used t test cmpnents in the circuit such as cnnectrs, switches, and suspected high resistance pints. NOTICE: The f ll w in g instrum ents: Am m eter, V ltm e te r, a n d O h m m e te r, e a ch h a ve a p a rtic u la r a p p lic a ti n f r tr u b le s h tin g electrical circuits. When using a am m eter r vltm eter, and the value being tested is unknw n always use the highest scale first and w rk dw nw ard t a m idscale reading whenever pssible. This w ill avid damage t the instrum ent. Never use an hm m eterr in a pw er circu it, r as a substitute f r a vltm eter r am m eter as damage t the instrum ent w ill result. AMMETER (Figure 12 and 15) Discnnect the circuit frm the pwer surce befre cnnecting the ammeter. The ammeter measures the amunt f electrical current, amperes, mving thrugh a cnductr. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter s psitive terminal is cnnected t the psitive (battery) side f the circuit and is negative terminal t the negative (grund) side f the circuit. OHMMETER (Figure 13 and 15) The hmmeter is an instrument designed t indicate resistance in hms. It is used t test the cnditin f a unit discnnected frm the circuit. Ohmmeter Calibratin When the hmmeter prbes are cnnected tgether, a circuit is cmpleted causing the meter needle t deflect. The needle shuld read ZERO hms, if it des nt, rtate the CAL r ADJ knb t ZERO the needle. When the prbes are held apart, the needle mves t the maximum (infinite) resistance side f the scale. The meter is nw ready fr use. Refer t figure 14 fr a typical applicatin f the hmmeter. VOLTMETER (Figures 14 and 15) The v ltm eter (prp erly bserved) w ill give the technician mre infrmatin than the ammeter, hmmeter and test light cmbined. Its applicatin fr trubleshting here is t measure the electrical pressure (vltage) drp in a resistance circuit (figure 14). T use a vltmeter fr trubleshting an electrical prblem, cnnect it in parallel with the existing circuit (figure 10). If the vltmeter is cnnected in series with the circuit being tested, the nature f the circuit wuld be changed and the reading wuld have n particular value r use. Cnnect the meter terminals accrding t plarity as shwn in figure 14. The dash munted vltmeter (in the vehicle) shuld als be bserved fr mnitring prper peratin f the generatr battery cranking mtr, and cranking circuit. In this applicatin, battery vltage drp can be mnitred while the engine is cranking; and after the engine is running, generatr utput vltage can be mnitred. This can be a valuable first step prir t diagnsing ther electrical prblems. WIRING HARNESS AND WIRES Every wire is a specific size with clred r striped insulatin that is indicated n the wiring diagrams. Insulatin clrs help t trace circuits and t make prper cnnectins. A bbreviatins and sym bls used fr indicating wire insulatin clrs and patterns are as fllws: BLK Black BLU... Blue BRN......Brwn PPL. CHK......Check TR.. C R......Crss YEL. GRN...Green II.... N A T......Natural WHT S G L...Single STR. O R N......Orange PNK..Yellw.Parallel.Stripe..Pink..Dark G R Gray DK.. Sme wires are gruped and taped tgether r encased in a split plastic casing. This gruping f wires is called a harness. Fr sme purpses, it is mre practical t use a single wire prtected by a braided tubing called a lm. AMPERES AM M ETER SCALE: 0 A m peres th r u g h 10 A m peres E = 1 Am pere F = 1.8 A m peres G = 9 A m peres OHM M ETER SCALE: 0 O hm s th r u g h In fin ity ( ) H = 5 O hm s I = 36 O hm s J = 115 O hm s K =350 O hm s Figure 15 Meter Scales F-01778

8 WIRING DIAGRAMS 11 WIRING DIAGRAMS 12 Wiring harnesses are jined by using a multiple plug and receptacle cnnectr blck, r a term inal pst chassis junctin blck. In the instrument panel area plastic insulated blade-type cnnectrs and screw-type terminals are used. Each harness r wire must be held securely in place by clips r ther hlding devices t prevent chafing f the insulatin. WIRE SIZE Wire size in a circuit is determined by the amunt f current, the length f the circuit and the vltage drp allwed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in crss sectin area measured in square millimeters. CIRCUIT MAINTENANCE AND REPAIR MAINTENANCE AND REPAIR All electrical cnnectins must be kept clean and tight. Lse r crrded cnnectins may cause a discharged battery, difficult starting, dim lights, and pssible damage t the generatr and regulatr. Wires must be replaced if insulatin becmes burned, cracked, r deterirated. T splice a wire r repair ne that is frayed r brken always use rsin flux slder t bnd the splice and insulating tape t cver all splices r bare wires. When replacing wire, it is imprtant that the crrect size wire be used as shwn n applicable wiring diagrams r parts bk. Each harness r wire must be held securely in place t prevent chafing r damage t the insulatin due t vibratin. Never replace a wire with ne f a smaller size r replace a fusible link with a wire f a larger size. WIRING CONNECTOR TERMINAL REPLACEMENT (BLADE TYPE) Remve r Discnnect (Figure 16) 1. Terminal lck tang. 2. Terminal (61). Install r Cnnect (Figure 17) 1. Pry up n the tang (70). 2. Terminal int the cnnectr. WIRE SIZE CONVERSION TABLE METRIC SIZE (mm) ON-VEHICLE SERVICE AWG SIZE Figure 16 Remving the Terminals frm the Cnnectr WIRING CONNECTOR TERMINAL REPLACEMENT (TWIN LOCK TYPE) Remve r Discnnect (Figure 18) Tl Required: J Terminal Remver 1. Cnnectr lck tangs. 2. Terminal lcks using J Terminal. Install r Cnnect 1. Pry ut the tangs. 2. Terminal int the cnnectr. Figure 17 Resetting the Lck Tang WEATHER-PACK CONNECTORS Special cnnectrs knwn as Weather-Pack cnnectrs (figure 19) require a special tl J fr servicing. This special tl is required t remve the pin and sleeve terminals. If remval is attempted with an rdinary pick, there is a gd chance that the terminal will be bent r defrmed. Unlike standard blade-type terminals, these terminals cannt be straightened nce they are bent. Make sure that the cnnectrs are prperly seated and all f the sealing rings in place when cnnecting the leads. The hinge-type flap prvides a back-up, r secndary lcking feature fr terminals. They are used t imprve the cnnectr reliability by retaining the terminals if the small terminal lck tangs are nt psitined prperly. Mlded-n-cnnectrs require cmplete replacement f the cnnectin. This means splicing a new cnnectr assembly int the harness. Envirnmental cnnectins ca n n t be re p la ce d w ith sta n d a rd c n n e c ti n s. In s tru c ti n s are p rvided w ith the W eather-p ack cnnectr and terminal packages. With the lw current and vltage levels fund in sme circuits, it is imprtant that the best pssible bnd at all wire splices be made by sldering the splices. Use care when prbing the cnnectins r replacing terminals in them, it is pssible t shrt between ppsite terminals. If tnis happens t the wrng terminal part, it is p ssib le t' at dam age m ay be d ne t c e rta in c m p n e r :. Alw ays use ju m p e r w ire s betw een cnnectrs fr circuit checking. Never prbe thrugh the Weather-Pack seals. When diagnsing fr pssible pen circuits, it is ften difficult t lcate them by sight because xidatin r terminal misalignment are hidden by the cnnectrs. Merely wiggling a cnnectr n a sensr r in the wiring harness may crrect the pen circuit cnditin. This shuld always be cnsidered when an pen circuit is indicated while trubleshting. Intermittent prblems may als be caused by xidized r lse cnnectins. METRI-PACK CONNECTORS The Metri-Pack cnnectrs use a pull-t-seat type terminal, as shwn in figure 19. The special tl required t remve the terminal is J A terminal remver. If remval is attempted with an rdinary pick, there is a gd chance that the terminal will be bent r defrmed. Refer t figure EE Remve r Discnnect (Figure 19) Tl Required: J Terminal Remver Primary lck (121) by lifting. Cnnectr sectins. Secndary lck (125) by spreading the sides f the hasp, thus clearing the staples and rtating the hasp (127). Terminal (131) by using J (128). Snip ff the ld terminal assembly. 5 mm f the wire insulatin (130). Clean Terminal barrel (124). Install r Cnnect (Figure 19) Terminal insulatr (134) n the wire. Slide the insulatr back n the wire abut 8 cm (3 inches). Terminal (131) n the wire. Rll crimp (132) and slder the terminal. Terminal insulatr (134) and the rll crimp (133). Terminal int the cnnectr. Secndary lck (125). Cnnectr sectins until the primary lck (121) engages. METRI-PACK CONNECTOR REPLACEMENT Remve r Discnnect (Figure 19) Tl Required J A Terminal Remver 1. Primary lck (121) by lifting. 2. Cnnectr bdy (137). 3. Cnnectr seal (120) by pulling the seal back nt the wires away frm the cnnectr bdy (137).

9 WIRING DIAGRAMS 13 WIRING DIAGRAMS , V \ , / VIEW A VIEW B C nnect r Seal m m (0.2 inch) 121. Prim ary Lck 131. Term inal 122. Secndary Lck Staple 132. Rll C rim p 123. Secndary Lck 133. Rll C rim p 124. Term inal Barrel 134. Term inal In su la t r 125. Secndary Lck 136. M etri-p ack Series 150 Fem ale Term inal 126. Lck Opened 137. C n n e ct r Bdy 127. Lck Opened 138. L cking Tang 128. J Terminal Remver 139. J Term inal Rem ver 129. W ire Figure 19 Weather-Pack and Metri-Pack Cnnectrs 139 F B 90. Jacket 91. Twisted Wires 92. Splice Clip 93. Crimp and Slder 94. Electrical Tape Wrap 95. Outer Electrical Tape Wrap. Figure 20 Twisted Wire Repair B Terminal (136) by inserting J (139) int the cnnectr bdy (137) t depress the lcking tang (138), then push the wire and terminal thrugh the cnnectr bdy (figure 20). Snip ff the ld terminal unless the terminal is t be reused, reshape the lcking tang mm (0.2-inch) f the wire insulatin (130). Clean Terminal cavity f the cnnectr bdy. Install r Cnnect (Figure 19) 1. Terminal (136) n the wire. Crimp and slder the terminal. 2. Terminal (136) int the cnnectr cavity by pulling the wire n the seal side f the cnnectr until the lcking tang (138) is fully seated. 3. Seal (120) by pressing the seal int the cnnectr bdy (137) until it is fully seated. 4. Cnnectr until the primary lck (121) engages. WIRING REPAIR The wire repair is very imprtant fr the cntinued reliable peratin f the vehicle. This repair must be dne as described in the fllwing prcedures. Twisted Wires (Figure 20) «+ Remve r Discnnect 1. Jacket (90). 2. Twisted wires (91). 106 V Jacket 101. A lu m in um /M yla r Tape 102. Drain W ire 103. S plice C lip 104. C rim p and S lder 105. E lectrical Tape Wrap 106. Drain W ire S plice Clip, C rim ped And S l dered O uter E lectrical Tape Wrap. B Figure 21 Twisted/Shielded Wire Repair 3. Insulatin frm the wire. Install r Cnnect 1. Splice clip (93). Crimp. Slder. 2. Electrical tape wrap (94) n wires. 3. Outer electrical tape wrap (95). Twisted Wires/Shielded Cable (Figure 21) Remve r Discnnect 1. Jacket (100). 2. Unwrap aluminum/mylar tape (101). 3. Drain wire (102). 4. Leads. 5. Insulatin n the leads. +«- Install r Cnnect 1. Splice clips (103). 2. Crimp and slder the splice clips (104). 3. Electrical tape (105) n the splices.

10 WIRING DIAGRAMS Aluminum/mylar tape by wrapping and taping. 5. Drain wire with a splice clip (106). Crimp and slder the splice clip. 6. Outer jacket electrical tape wrap (107). SPECIAL TOOLS

11 1988 C/K TRUCK SECTION A PAGE DESCRIPTION PAGE DESCRIPTION 2 POWER DISTRIBUTION (GASOLINE) 34 ELECTRONIC CONTROL MODULE (ECM)-OUTPUTS (DIESEL) 3 POWER DISTRIBUTION (DIESEL) 36 ECM CHART (DIESEL) 4 AUXILIARY BATTERY(RPO TP2) 38 AUTO TRANSMISSION KICKDOWN SOLENOID (M40) 5 FUSE BLOCK 39 HEATER 6 CONVENIENCE CENTER 40 AIR CONDITIONING 7 HEADS & PARKING S (BASE) 42 BRAKE WARNING SYSTEM 8 HEADS & PARKING S (QUAD) 43 INSTRUMENT PANEL S (ELECTRONIC) 9 MARKER S (QUAD ONLY) 4 4 INDICATOR S (ELECTRONIC) 11 ROOF MARKER S 46 SEAT BELT WARNING BUZZER 12 HAZARD S 47 FOUR WHEEL DRIVE INDICATOR 14 DIRECTIONAL S 48 DOME S 16 HORNS 49 CONVENIENCE LIGHTING PACKAGE 17 START 50 CARGO 18 START (DIESEL) 51 RADIO EQUIPMENT 19 IGNITION 52 RADIO EQUIPMENT 20 THROTTLE BODY INJECTION 53 POWER WINDOWS 21 HOT FUEL HANDLING 54 REAR DEFOGGER 22 GLOW PLUGS (DIESEL) 55 POWER DOOR LOCKS 24 ENGINES CONTROLS (DIESEL) 56 WIPER/WASHER 26 FUEL CONTROL & IDLE AIR CONTROL 57 CRUISE CONTROL 27 AUXILIARY COOLING FAN 58 REAR WHEEL ANTI-LOCK 29 ELECTRONIC CONTROL MODULE (ECM)-INPUTS 59 BACK-UP S 30 ELECTRONIC CONTROL MODULE (ECM)-OUTPUTS 61 END GATE & SIDE CLEARANCE S 32 ECM CHART 62 TAIL S 33 ELECTRONIC CONTROL MODULE (ECM)-INPUTS (DIESEL) 64 LICENSE S INDEX SECTION A -PAGE 1

12 d- - a - 03; O r 9i ; e>r.a; i SPLICE 2 ^ A W<» -' M w V :' X» -I < j V BLK BLK SHEET METAL GRD REAR POWER DISTRIBUTION LB4, L03, L05, L19 SECTION A-PAGE 2 AUXILIARY BATTERY RPO-TP2 (IF EQUIPPED) SHEET METAL FUSE BLOCK

13 n n n n + SHEET + - RH METAL LH BATTERY GRD BATTERY FRONT FUSE BLOCK REAR POWER DISTRIBUTION LH6, LL4 DIESEL SECTION A-PAG E 3

14 JUNCTION BLOCK A O O V J O RUST FUSIBLE LINK ' SPLICE 2 tedoocgdoo Cgp I J0*_J tcm tgtt 1** M f EDO G C i D 0 GCi O O D C 0 0 m s Q Q O O O O O O»T 0 fh A I C M M II II II II II" II II II L L " FRONT I T BRN- 1 T a/is f f l / B H /E f il/ll E /E e / e e / ts E /E E /E REAR RUST FUSIBLE LINK ' SPLICE 2 FUSE BLOCK TO HEATER A/C SPLICE 50 AUXILIARY BATTERY BLK- 5 ) D Ui C * FROM PANEL DIMMER SWITCH FROM LH JAMB SW FROM HEATER A/C BLK FROM RADIO FROM CIGAR LIGHTER FROM SEAT BELT SW 2*S BLKa n a s west»<wamr m c*unt it f le f u f r O M EW MfOQ tfam I Mt* MfOO -I B *» ANT SC*M0 L* - jj n* * c SffitWii * t e On 2 CL CO 0 01 WOO 4WMII10I AUXILIARY BATTERY RELAY RED- S BLK/RED- GROMMET A A A A A FROM CONVENIENCE CENTER Q Q3 (H3 Q a C3GD 3 CD a CONVENIENCE CENTER l L r ID BRN BLK BRN - 150*.8 BLK - AUXILIARY BATTERY RPO TP2 SECTION A -PAGE 4

15 B R N -H E A TE R -A IR CONDITIONING 40.8 ORN/WHT-INTERIOR LPS RED-IGN SW -BATT ORN LT SWITCH-CONV CENTER ORN IGNITION BRN-IGN SW -A C C BRN/WHT-REAR WHEEL ANTILOCK W H T -W /S WASHER WIPER 43.8 YEL-RADIO PNK POWER WINDOWS BRN-IGN SW -A C C 60.8 ORN/WHT-POWER/ACC RED-IGN SW -BATT PPL/WHT-CRANK PPL-STARTER SOLENOID FEED 39.8 PNK/BLK IGN SPLICE PNK IGN SW -IG N SHUNT (TYP.) DK BLU-DIR SIGN FLASHER 75.8 DK BLU-BACKUP SW PNK/WHT ECM/IGNITION PNK IGN SW -IG!N N I RED-INJECTOR " A ^ J 44.8 DK GRN-LT SW RHEOSTAT GAS ENGINES ONLY FRONT 8.35 GRA-PANEL S RED-BATTERY ORN-HAZARD FLASHER REAR FUSES AMP COLOR TAN RED LT BLU YEL WHT FUSE BLOCK SECTION A-PAGE 5

16 8.5 GRA -----CRUISE CONTROL 39.8 PNK/BLK BRN BLK ORN/BLK TURN SIGNAL FLASHER BLK/WHT 40.8 ORN WHT WHT DK BLU DK BLU BLK DOME 16.8 PPL POWER DOOR LOCKS REAR DEFOGGER HORN RELAY POWER WINDOWS REAR DEFOGGER CARGO POWER WINDOWS INTERIOR COURTESY S AUXILIARY BATTERY RELAY INTERIOR COURTESY S BLK 9.8 BRN BLK ORN ORN/BLK ORN/BLK 28-5 BLK DK GRN PNK BRN FOUR WHEEL- DRIVE POWER DOOR LOCKS YEL BLK BLK- ROOF MARKER- S 8.35 GRA ORN LT GRN- S f f l Gp 9.8 BRN BLK AUDIO ALARM MODULE 39-8 PNK/BLK- FRONT REAR CONVENIENCE CENTER SECTION A-PAGE 6

17 FROM ENGINE COOLANT FAN (L19 ONLY RIGHT HAND HIGH & LOW BEAM HEADS LEFT HAND HIGH & LOW BEAM I Z HEAD FROM WINDSHIELD WASHER PUMP HEAD S & PARKING S (BASE) SECTION A-PAG E 7

18

19 RH SIDE MARKER JUNCTION BLOCK DIESEL TO RIGHT HAND PARK & TURN SIGNAL S TO LEFT HAND PARK & TURN SIGNAL S Z 2 a: a. m cd CO 2 cc CO A O) 0> O ij SPLICE LH SIDE MARKER MARKER S (QUAD ONLY) SECTION A -P A G E 9

20 SECTION A-PAG E 10 V

21 JUNCTION BLOCK A r*j 0 -, O - - V GAS SPLICE 2 y I _j (/) LU Ui w HI LJ t -> 5 * * Q O J U J? CD OC O O W r- 1- < CS$2 I O UJ QC O / DIESEL ONLY FUSIBLE LINK RED GROMMET l~? 0 * ~ l 0 \ Q )~ 3 S * ~ ) 0 0 Q *» ~ l \ AC HT* ***** 0 Ca G C i D 0 C! 0 0 C ^ ) 0 D O Q rfcj * MMl l*s G s 3 0 GAS ENGINES ONLY I ii ii ii ii FRONT ENGINE j RED- 130* c T l FUSE BLOCK SPLICE 2 r I a a / l l i t 51/11 51/E 51/S 51/S REAR SPLICE RED ORN RED BRN - TO CONVENIENCE CENTER TO CIGAR LIGHTER HEADS SWITCH FROM PANEL DIMMER SWITCH FROM LH JAMB SW FROM HEATER A/C FROM RADIO FROM CIGAR LIGHTER FROM SEAT BELT SW BLK - j CD FROM l/p CLUSTER CONNECTOR FROM CONVENIENCE CENTER SPLICE 150 RIGHT HAND MARKER FRONT IDENTIFICATION < C * FRONT IDENTIFICATION TERM TERM TERM TERM TERM TERM TERM x si s» " V» H * Z CD s 00 O in m ^»- Ift i IT) TO CONVENIENCE CENTER TO RADIO FRONT IDENTIFICATION TO A/C Z cc GO 9-8 BRN - DIESEL ONLY I I TERM «CO 00 tf> in l/p TERM : J : r i «L D ] r : : CONVENIENCE CENTER 9.8 BRN Q Q 3» jn 3 isl?3it q 3 I bf»l r*l i»i a BLK LEFT HAND MARKER WHT TERM BLK WHT BLK ROOF MARKER S SECTION A-PAGE 11

22 FROM RH HEAD (BASE) > l/p CLUSTER CONNECTOR FROM LH HEAD (BASE) HAZARD S SECTION A-PAG E YEl * 18.8 YEL -

23 R.H. TAIL, STOP, TURN Lf) FRAME L.H. TAIL, STOP, TURN SIGNAL & BACK UP CAB-CHASSIS ONLY HAZARD S SECTION A-PAGE 13

24 FROM RH HEAD (BASE)» BLK FROM ENGINE COOLANT FAN (L19 ONLY) FROM RH HORN BLK 51.8 DK BLU * a RH SIDE MARKER (QUAD) FROM PANEL DIMMER SWITCH D d ~ D O O 0 O ^ D A X MTU O O O d O O O B C,sO OQ O 01 G O O O D O D O O O IT O fm *; nr ir ii.'in: n~ n ii ii - t FRONT O BLK " IT IT s / e a /» 51/E 5L/U H/TE 51/S SI/TS Si/TS 51/13 51/19 ^ FUSE BLOCK REAR wmt l/p CLUSTER CONNECTOR BLK DK BLU SPLICE BLK j a * a c in 4 RIGHT HAND PARK & TURN SIGNAL S I CD * FROM CONVENIENCE CENTER CONVENIENCE CENTER I B BLK LT BLU 15.8 DK BLU LT BLU l/p > a 00 (STEERING COL. SWITCHES) LEFT HAND PARK & TURN SIGNAL S (D; FROM WINDSHIELD WASHER PUMP FROM LH HORN (QUAD) BLK FROM RH HEADS (QUAD) { FROM LH HEAD (BASE) DIRECTIONAL S SECTION A-PAG E BLK ' 14.8 LT BLU LH SIDE MARKER (QUAD) \ s 12 J I L 9,3 t 3 ] r 12 ) B 92 9 i : : DK GRN 18.8 YEL DK GRN DK GRN YEL 16.8 PPL 15.8 DK BLU 14.8 LT BLU / f s DIRECTIONAL SIGNAL SW 19.8 DK GRN 18.8 YEL YEL

25 R.H. TAIL. STOP, TURN BLK O J > 00 _J - I CO CQ CO 00 Ifl tf> FRAME 120B9200 L.H. TAIL, STOP, TURN SIGNAL & BACK UP CAB-CHASSIS ONLY DIRECTIONAL S SECTION A-PAGE 15

26 BLK FROM RH PARK & TURN SIGNAL S HORN RELAY 17 p N 19 IB M 18 1 "16 L K 27 FROM ENGINE COOLANT FAN (LI 9 ONLY) 15 J 15 5L 14 H II - 28 G F e 159 D HAZARD RIGHT HAND HORN (BASE & QUAD) DK G RN DK GRN BLK DIRECTIONAL SIGNAL SW TO CIGAR LIGHTER ORN LEFT HAND HORN (QUAD ONLY 29 ( DK GRN DK G R N cc * Q S l/e /11 B l/i) 51/E l/p S l/s 51/E SI/TS I X ) O O O O GBD 0 0 O O TOP MAI» II " II H II II II CRANK 51/E S l/e R FROM LH PARK & TURN SIGNAL S BLK L D] h 0 r : 24 ; 5 6 FRONT FUSE BLOCK REAR HORN SECTION A PAGE 16 FROM LH HEAD

27 2 32 BLK G«Q Ci5Q QsC) D D Q.pQ O O C5* J O D MJ* PANEL IPS t D D GiO D Q QO stf w cm* ii n ~ ii ii ii ii 11 r r - T T AUXILIARY BATTERY RP0-TP2 (IF EQUIPPED) SHEET ( Q ) METAL FRONT FUSE BLOCK REAR START LB4, L03, L05, LI9 SECTION A-PAGE 17

28 n n _ n n _j_ ~h SHEET RH METAL LH BATTERY GRD * BATTERY O ] ENGINE " GRD FRONT FUSE BLOCK REAR START LH6, LL4 DIESEL SECTION A-PAGE 18

29 FROM AIR SWITCH ^ PNK BLK B6 REAR IGNITION LB4, L03, L 05, LI9 SECTION A -PAGE 19

30 OXYGEN SENSOR 465 = 4 3 * 7 7» THROTTLE POSITION SENSOR BLK - SPLICE 452 J Z TO COOLANT TEMP SENSOR BLK PPL S »0 ELECTRONIC CONTROL MODULE CONNECTORS DK BLU OK BLU GRA GRA BLU TO MAP SENSOR GRN RED INJECTOR BLU RED- SPLICE > RED GRN RED WHT ENGINE D f O O 0 * 0 O 0 0 * 0 O O 0 * Q Q Q ^ i O D ICR KM M M IP s m i Q O 0 1 M L IP 1 M * 1 IQ Q 0 QsQ Q D OO tienta II II II II II II u..i I -g FRONT c«mk U I f a / a / S l/b Sl/M) Sl/TS si/h e / e a /is i si/b a /is......j E- REAR FUSE BLOCK RED THROTTLE BODY INJECTION LB4, L03, L05, LI9 SECTION A-PAG E 20

31 HOT FUEL HANDLING MODULE FUEL PUMP IGNITION TAN/WHT 39.8 PNK/BLK BLK/WHT TO l/p CLUSTER CONNECTOR TO CONVENIENCE CENTER USPLICE 39 ELECTRONIC CONTROL MODULE CONNECTORS TAN/WHT kgfs O O K ) 0 ^0 A C HTR U Lf a/is m dp t * X 5 2 < K Op sah q 0 q Q C l 0 O O CTb> Q«"i G O C2 *j O Q Q s O A c T 0 Q 0 0 Q l Q 0 0 D C STCH* H*7 - - CMNK II II H ' IE FRONT n ii ri~ FUSE BLOCK a / 51/B si/a a/is a / s a/e sitb a/is 4. J L REAR FROM ESC ILB4. L03. L05I E 3 ED [ED fw l 0 _ i I» r a I llfil >'E3 TO ECM AUXILIARY COOLING FAN RELAY { L I9 & C60) ENGINE 39.8 PNK/BLK i/p < (- <*> i h a r*n ] [5 3,4EHI [ j l 6 f * * 0 ( t - z j BLK/WHT - [ I 3 40 IS I 2 31 F i f f IB I U ? 12 J 1 1 f 9f , L Dl r 93? : FUEL METER & PUMP SPLICE 450 \ lakuuix BLK/WHT FROM EVRV SOL FROM ALOL BLK/WHT TAN/WHT TAN/W HT- FROM FUEL PUMP RELAY HOT FUEL HANDLING (L05, LI9) SECTION A-PAGE 21

32 FROM A/C COMP (IF EQUIPPED) FROM W/S WIPER MOTOR BLK BLK - ENGINE GRA GRA FROM RWAL MODULE FROM FUEL PRESSURE SWITCH FROM WATER IN FUEL SENSOR FROM RH BATTERY ( - ) FUSIBLE LINK RIGHT BANK GLOW PLUG SPLICE 509 SPLICE 503 TO FUEL PUMP RELAY PPL/WHT SPLICE 509 GC GLOW PLUG CONTROLLER O R N LT GRN/BLK BLK TO GLOW - PLUGS WAIT SPLICE GRN- SPLICE RN- HI cc i FROM LH BATTERY (- LEFT BANK GLOW PLUG TO COLD ADVANCE -4- SOLENOID & COLD ADVANCE CONTROL RELAY GLOW PLUGS-LH 6 DIESEL SECTION A-PAGE 22 JUNCTION BLOCK & -+ V BLU----- FUSIBLE LINK SPLICE 2

33

34 COLD ADVANCE FAST IDLE TEMPERATURE SWITCH l/p CLUSTER CONNECTOR FUEL PRESSURE WATER IN FUEL SENSOR FUEL HEATER DIESEL ENGINE CO NTRO LS-LH6 SECTION A -P A G E PNK/BLK-

35 COLD ADVANCE CONTROL l/p CLUSTER CONNECTOR FUEL PRESSURE WATER IN FUEL SENSOR FUEL HEATER J 39.8 PNK/BLK - DIESEL ENGINE CONTROLS LL4 SECTION A-PAGE 25

36 IDLE AIR CONTROL (L19) HOT FUEL HANDLING MODULE TO CONVENIENCE CENTER IDLE AIR CONTROL STEPPER MOTOR <S> 442 Pnrn _ 443 I IDLE AIR CONTROL (LB4, L03, L05) FUEL PUMP RELAY FUEL CONTROL & IDLE AIR CONTROL LB4, L03, LOS, LI9 SECTION A-PAGE ORN ,0 PNK/BLK IN-LINE FUSE

37 JUNCTION BLOCK A O O - V 2.5 RED- L FUSIBLE LINK SPLICE BLK/WHT- TO HOT FUEL HANDLING MODULE l/p CLUSTER CONNECTOR ':; U U n 4 00 w u 31 n u,n 937 z 14 e n 39 <e OD 15 u - n 9> * u> 25 LJ11 n 6 * u b A ' 38-8 PNK/BLK 1 SPLICE PNK/BLK AUXILIARY COOLING «7 FAN RELAY : II J 1 1 ft : 18 " ? 9 1 L 3 >] b 0 r 937? :? / 5 8 TO CONVENIENCE CENTER DK GRN \ AUXILIARY FAN TEMP SWITCH 39.8 PNK/BLK- v T sp SPLICE BLK/RED BLK/WHT. U AUXILIARY COOLING FAN BLK FROM RIGHT HAND HEAD (BASE) B LK SPLICE FROM RIGHT HAND HEADS (DUAL) G i O O G C i A-C MTU C "G OO Qmj O 0 CCMK3N m io O PA*K I f c c I O O O O O 0 MJ A PANCt L «O O O O GsD 0 O O STOP HA2 II II II II CRANK II II W E E/MI S l/e S l/b S l/e a/e a/e s /tsi GO/S a/e RH FROM RH HORN FROM RH PARK & TURN SIGNAL S FRONT FUSE BLOCK AUXILIARY COOLANT FAN LI9 &C60 SECTION A-PAGE 27

38 SECTION A-PAGE 28

39 THROTTLE POSITION SENSOR OXYGEN SENSOR 0 1 S t-i 2 5 * u r 1 UkOCS di 0, r a,0. i 2 0 A T i l * ftu * C MTU CTSV 0 1 m 1 U2SJ 0 ECMIGN M K D O PAM I f 1 > 0 * 1 0 L 5-A J MJ A H M l L»S 0 0 D 0 GsO D STOPHA2 FRONT FUSE BLOCK (L05. L19 ONLY) ELECTRONIC CONTROL M O D ULE-INPUTS LB4, L 03, L05, LI9 SECTION A -P A G E 29

40 ELECTRONIC SPARK TIMING EST SIGNAL EST REF. PULSE HI EST BYPASS EST REP. PULSE LO WHT PPL/WHT TAN/BLK STEPPER MOTOR 441 <S> \ I 444 IDLE AIR CONTROL (LB4. L03. L05) LT GRN/WHT LT BLU/BLK LT BLU/WHT LT GRN/BLK E.V.R.V. (L05, LI9, LB4 HEAVY DUTY ONLY) BLK/WHT GRA PNK/BLK IDLE AIR CONTROL (LI9) 444 I44? I n i I i I W i LT GRN/BLK LT GRN/WHT LT BLU/WHT LT BLU/BLK BLK/WHT BLK/WHT WHT WHT AIR SW ITCH PNK/BLK BRN SPLICE PPL/WHT TAN/BLK BLK/RED G R A BRN PPL/WHT TAN/BLK BLK/RED GRA GRA BRN BRN BRN TAN LB4.L03 ONLY BLK/WHT BLK/WHT INJ GRN WHT GRN BLU DK GRN/WHT TAN/WHT GRN BLU DK GRN/WHT TAN/WHT PNK/BLK PNK/BLK BLU RED- SPLICE PNK/BLK RED/WHT RED ORN ORN PNK/BLK RED/WHT RED ORN ORN PNK/BLK BLK/WHT BLK/W HT---- FUEL PUMP OIL PRESSURE SWITCH PNK/BLK ORN RED/WHT TO HOT FUEL HANDLING MODULE (L05.L19) TO FUEL METER & PUMP TAN/WHT LB4.L03 ONLY ' * «t c a DK GRN/WHT FUEL PUMP RELAY PNK/BLK BLK/WHT ORN ELECTRONIC CONTROL MODULE-OUTPUTS LB4, L03, L05, LI9 SECTION A-PAGE 30 V SPLICE 920 "T \ PNK/BLK IN-LINE FUSE EGR SOLENOID LB4.L03 ONLY

41

42 CIRCUIT NO. WIRE SIZE COLOR CAVITY DESCRIPTION CIRCUIT NO. WIRE SIZE COLOR CAVITY DESCRIPTION DK GRN/WHT A1 FUEL PUMP RELAY DRIVE A2 NOT USED A3 NOT USED GRA A4 EGR SOLENOID BRN/WHT A5 SYSTEM CHECK PNK/BLK A6 12V IGNITION FUSED * TAN/BLK A7 AUTO TRANS KICKDOWN RELAY TAN/BLK A7 UPSHIFT ORN A8 SERIAL DATA WHT/BLK A9 ASS Y LINE DIAG. LINK BRN A 10 SPEED SIGNAL PPL A 1 1 5V RETURN A BLK/WHT A12 SYSTEM RETURN ORN B1 12V BATTERY FUSED TAN/WHT B2 ELEC FUEL PUMP FUSED FEED BLK/RED B3 DISTRIBUTOR REF LOW B4 NOT USED PPL/WHT B5 DISTRIBUTOR REF HIGH B6 NOT USED YEL/RED B7 SPARK RETARD CONTROL 59.8 DK GRN B8 AIR CONDITION B9 NOT USED * ORN/BLK B10 PARK/NEUTRAL SWITCH B11 NOT USED B12 NOT USED * AUTO TRANS ONLY C1 NOT USED BRN C2 AIR SWITCH SOLENOID LT GRN/BLK C3 STEPPER COIL B LOW LT GRN/WHT C4 STEPPER COIL B HIGH LT BLU/WHT C5 STEPPER COIL A HIGH LT BLU/BLK C6 STEPPER COIL A LOW * LT BLU C7 AUTO TRANS KICKDOWN RELAY C8 NOT USED PPL/WHT C9 CRANK DISCRETE FUSED YEL C10 COOLANT TEMPERATURE LT GRN C11 MANIFOLD ABSOLUTE PRESS C12 NOT USED DK BLU C13 THROTTLE POSITION SENSOR GRA C14 5 V SENSOR REFERENCE C15 NOT USED ORN C16 12V BATTERY FUSED BLK/WHT D1 SYSTEM RETURN BLK D2 5V RETURN B D3 NOT USED WHT D4 HEI SPARK TIMING TAN/BLK D5 HEI BYPASS TAN D6 OXYGEN SENSOR LOW PPL D7 OXYGEN SENSOR HIGH D8 NOT USED D9 NOT USED D10 NOT USED D11 NOT USED D12 NOT USED D13 NOT USED GRN D14 INJECTOR B DRIVE D15 NOT USED BLU D16 INJECTOR A DRIVE * AUTO TRANS ONLY (MD8 ONLY) ELECTRONIC CONTROL MODULE LB4, L03, L05, LI9 SECTION A-PAG E 32

43 ENGINE SPEED SENSOR TO ECM COOLANT TEMP SENSOR THROTTLE POSITION SENSOR QsSb ip T U M p r 0 0 A C MTU CT*v GO 1 i f l f t DO 0 IC N IM tm rt> OBO 0 0 GO M M t IPS 0 CD 0 0 U *«J H O f*u U 0 FRONT FUSE BLOCK REAR TO STOP/ TCC SWITCH SPLICE 439 TO COLD ADVANCE RELAY ELECTRONIC CONTROL M ODULE-INPUTS LH6 DIESEL SECTION A -PAGE 33

44 COLD ADVANCE GLOW PLUG INHIBIT RELAY TRANSMISSION CONVERTER CLUTCH SOLENOK) COLO ADVANCE CONTROL « LT GRN/BLK - SPLICE LT GRN/BLK - SPLICE OK GRN PPL PNK/BLK - ENGINE GRD BLK - FROM A/C * COMPRESSOR FROM RWAL Z Q. MODULE 00 FROM W/S 0) WIPER MOTOR DK GRN DK GRN BLK PNK/BLK - EGR DUMP : 7 t ^ LT BLU PNK/BLK - SPLICE PNK/BLK PNK/BLK PNK/BLK i PNK/BLK - EGR VALVE k c S i GRA PNK/BLK EPR VALVE : k c ] 53R PNK/BLK DK GRN DK GRN TO COLD ADVANCE/ FAST IDLE TEMP SWITCH l/p GLOW PLUG CONTROLLER ELECTRONIC CONTROL MODULE-OUTPUTS LH6 DIESEL SECTION A-PAG E ,8 LT GRN/BLK BLK ? i t 9 H L I TO CONVENIENCE CENTER *- i 00 2

45 TO ECM FRONT FUSE BLOCK REAR SPLICE 439 ELECTRONIC CONTROL M ODULE-OUTPUTS LH6 DIESEL SECTION A -PAGE 35

46 CIRCUIT NO. WIRE SIZE COLOR CAVITY DESCRIPTION LT GRN A1 MANIFOLD ABSOLUTE PRESS DK BLU A2 THROTTLE POSITION SWITCH YEL A3 COOLANT TEMP. SENSOR A4 NOT USED A5 NOT USED BLK A6 ASS Y LINE DIAG. LINK A7 NOT USED WHT A8 ENGINE SPEED SENSOR BRN A9 SPEED SIGNAL WHT/DK GRN A10 DRIVE A11 NOT USED GRA A12 5V REF. VOLT B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED CIRCUIT NO. WIRE SIZE COLOR CAVITY DESCRIPTION BLK C1 SYSTEM RETURN BLK C2 SYSTEM C3 NOT USED C4 NOT USED * TAN/BLK C5 TORQUE CONVERTER CLUTCH C6 C7 NOT USED C8 NOT USED C9 NOT USED GRA C10 EGR DIAGNOSTIC CONNECTOR LT BLU C11 EGR SOLENOID DK GRN C12 EPR SOLENOID C13 NOT USED PNK/BLK C14 12V IGNITION FUSED C15 NOT USED ORN C16 12V BATTERY FUSED D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 D14 D15 D16 NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED NOT USED * AUTO TRANS ONLY ELECTRONIC CONTROL MODULE LH6 DIESEL SECTION A-PAG E 36

47 SECTION A-PAGE 37

48 - r JUNCTION BLOCK A O O V LU c FUSIBLE LINK < > SPLICE RECTIFIER ASSEMBLY - 0 h PPL SPLICE 420 RESISTOR 510 OHM.50 WATT SPLICE LT BLU _ c P & 1..i ) H 4 2 * ] 5 -J u. 4)71 7..J* ) - > 'SS I " I ' 2 I h H 1 *,6I l» 1 4 7** } TO ECM TRANSMISSION KICKDOWN RELAY PPL GROMMET CN CM (N ^ ^ ^ Q. 00 *4 * TAN/ SPLICE TAN/BLK ELECTRONIC CONTROL MODULE CONNECTORS < (- TRANSMISSION KICKDOWN SOLENOID REAR BRAKE ANTI LOCK MODULE CONNECTOR PPL ( ) E H STOP/TCC SWITCH CONNECTOR i3r TO ALDL TO FOUR WHEEL DRIVE HARNESS (IF EQUIPPED) PPL PPL AUTOMATIC TRANSMISSION KICKDOWN SOLENOID (GAS ENG. ONLY) SECTION A-PAGE 38

49 HEADS SWITCH 8.5 GRA BLK HEATER TO CONVENIENCE CENTER *.5 GRA BLK HEATER LT BLU BRN ORN BLOWER SWITCH YEL CD Ift O *_J CD O in < a u> 00 2! 9 u> «00 u> YEL LT BLU ORN r «i i ONLY BLK BRN - SPLICE ORN ORN LT BLU I I C42 ONLY L OJ r» la U) r L-J RESISTORS I I I FROM INST CLUSTER CONN ORN FROM RADIO BLOWER MOTOR BLK HEATER SECTION A -P A G E 39

50

51 SPLICE TO CONVENIENCE CENTER 00 CO <T> Ol TO RADIO TO BULKHEAD CONNECTOR A/C CON TROLLER BATT DIM PARK IGN PRESS. SW A WD F/B POT VOLT TO MTR TO MTR TO F/B POT 902 MD MTR MD MTR RD MTR RD MTR RD F/B POT FAN REL # FAN REL # A/C CLUTCH REL MODE DOOR MOTOR TEMP DOOR MOTOR AIR INLET VALVE RED 66-8 DK GRN BLK/WHT RESISTOR GRA BLK BRN BLOWER RELAY #1 BLOWER RELAY # 2 BLOWER MOTOR AIR CONDITIONING SECTION A-PAGE 41

52 33.5 TAN/WHT l/p CLUSTER CONNECTOR REAR WHEEL ANTI LOCK MODULE CONNECTOR 33.8 TAN/WHT IN-LINE DIODE (POWER BRAKES ONLY) 33-5 TAN/WHT >GD BRAKE PRESSURE WARNING SWITCH TAN/WHT SPLICE TAN/WHT L SPLICE 33 MANUAL BRAKES ONLY 33.5 TAN/WHT 33*.5 TAN/WHT I ) I I ID t l [ III I v> 12 L J, 11 I < m r n CC PARK BRAKE SWITCH CLOSED WITH PARK BRAKE ON BRAKE WARNING SYSTEM SECTION A-PAG E 42

53 HEADS SWITCH A/C CONT ROLLER BATT. - 2 DIM - 8 PARK - 9 IGN PRESS. SW A MD F/B POT VOLT TO MTR TO MTR TO F/8 POT MD MTR MO MTR RD MTR RD MTR RD F/B POT FAN REL # FAN REL # A/C CLUTCH REL >966 ILLUMINATION HI-BEAM LEFT TURN RIGHT TURN ALTERNATOR FUEL GAGE OIL PRESS PARK/ANTI-LK ENGINE TEMP IGN SEAT BELT LP. -SPEED SENS HI SPEED SENS-LO SERVICE ENG. SPEED SIGNAL (CRUISE) SPEED SIGNAL (ECM) IGN SHIFT LP. SPEED SIGNAL (RWAL) INSTRUMENT PANEL CLUSTER (GAS ENGINES) ILLUMINATION li-beam LEFT TURN RIGHT TURN ALTERNATOR FUEL GAGE OIL PRESSURE PARK/ANTI-LK ENGINE TEMP IGNITION LOW COOLANT SEAT BELT LP SPEED SENS-H I SPEED SENS-LO SPEED SIGNAL (CRUISE) SPEED SIGNAL (ECM) IGNITION SERVICE ENGINE WAIT LP. W.I.F. SPEED SIGNAL (RWAL) INSTRUMENT PANEL CLUSTER (DIESEL ENGINES) INSTRUMENT PANEL S SECTION A -P A G E 43

54

55 8 ILLUMINATION 1 1 HI BEAM 14 -LEFT TURN 15 -RIGHT TURN 25 -ALTERNATOR 30 -FUEL GAGE 31 -O IL PRESSURE 33 -PARK/ANTI LK 35 -ENGINE TEMP 39 -IGNITION 69 -LO W COOLANT SEAT BELT LP SPEEO SENS HI SPEED SENS LO -SPEED SIGNAL (CRUISE) SPEED SIGNAL (ECM) IGNITION -SERVICE ENG SERVICE ENGINE WAIT LP. W I F. SPEED SIGNAL (RWAL) IGNITION SW ITCH INDICATOR S SECTION A -PAGE 45 ^