GMC Suburban V1500 1990 - ELECTRICAL COMPONENT LOCATOR 1989-90 ELECTRICAL COMPONENT LOCATIONS General Motors Corp. - Electrical Components - Trucks

GMC Suburban V1500 1990 - BUZZERS, RELAYS & TIMERS

GMC Suburban V1500 1990 BUZZERS, RELAYS & TIMERS LOCATION

Component	Location
A/C-Heater Blower Relay	On evaporator case, on right side of firewall. See Fig. 1 .
Air Injection Control Relay
1989	On center of firewall. See Fig. 2 .
1990	On center of firewall.
Downshift Relay (THM 400/3L80)
5.7L Component Location	On right side of firewall. See Fig. 3 .
7.4L Component Location	On right side of firewall. See Fig. 4 .
5.7L Component View	On right side of firewall. See Fig. 5 .
7.4L Component View	On right side of firewall. See Fig. 6 .
Auxiliary Cooling Fan Relay	On left fender front panel, near firewall.
Check Engine Light Relay	On center of firewall.
Cold Advance Control Relay (6.2L)	On right side of firewall, in engine compartment.
Fuel Pump Relay
5.7L Component Location	On right side of firewall, on relay block. See Fig. 3 .
7.4L Component Location	On right side of firewall, on relay block. See Fig. 4 .
5.7L Component View	On right side of firewall, on relay block. See Fig. 5 .
7.4L Component View	On right side of firewall, on relay block. See Fig. 6 .
Hazard Flasher Relay	On convenience center.
Horn Relay	Behind dash, left of steering column. See Fig. 7 .
Power Door Lock Relay	Behind dash, on left side of steering column support. See Fig. 8 .
Power Window Relay	Under center of dash.
Relay Block	On right side of firewall.
Turn Signal Flasher Relay	On fuse block.
Warning Buzzer	On convenience center.

GMC Suburban V1500 1990 - CIRCUIT PROTECTION DEVICES

GMC Suburban V1500 1990 CIRCUIT PROTECTION DEVICES LOCATION

Component	Location
Circuit Breakers	In fuse block.
Fuse Block
5.7L Component Location	Under left side of dash. See Fig. 3 .
7.4L Component Location	Under left side of dash. See Fig. 4 .

GMC Suburban V1500 1990 - CONTROL UNITS

GMC Suburban V1500 1990 CONTROL UNITS LOCATION

Component	Location
Air Injection Diverter Module
1989	On center of firewall. See Fig. 2 .
1990	On center of firewall.
Cruise Control Module	On right side of steering column support. See Fig. 9 .
Diesel Elect. Control (DEC) Module	Under right side of dash.
Electronic Control Module (ECM)
5.7L Component Location	Under right side of dash. See Fig. 3 .
7.4L Component Location	Under right side of dash. See Fig. 4 .
5.7L Component View	Under right side of dash. See Fig. 5 .
7.4L Component View	Under right side of dash. See Fig. 6 .
Elect. Spark Control (ESC) Module
5.7L Component Location	On top right side of engine. See Fig. 3 .
5.7L Component View	On top right side of engine. See Fig. 5 .
Fuel Pump Module (5.7L H/D)	Under left side of dash. See Fig. 3 .
Glow Plug Controller (6.2L)	On left rear of intake manifold. See Fig. 10 .
Windshield Wiper Delay Module	On bottom of steering column.

GMC Suburban V1500 1990 - SENDING UNITS & SENSORS

GMC Suburban V1500 1990 SENDING UNITS & SENSORS LOCATION

Component	Location
Air Cleaner Sensor (7.4L Carb.) (1989 ONLY)	On left side of air cleaner housing.
Cold Advance Control (CAC) & Fast Idle Solenoid Temp. Sensor (6.2L)	On rear of right cylinder head.
Coolant Temp. Sending Unit/Switch
4.8L (1989 ONLY)	On front of motor, below thermostat housing.
5.7L & 6.2L	On front of left cylinder head.
7.4L
Carbureted (1989 ONLY)	On right or left cylinder head, above exhaust manifold. See Fig. 2 .
Left View	On right or left cylinder head, above exhaust manifold. See Fig. 6 .
Right View	On right or left cylinder head, above exhaust manifold. See Fig. 11 .
Coolant Temperature Sensor
5.7L Component Location	In right front corner of intake manifold. See Fig. 3 .
7.4L Component Location	In right front corner of intake manifold. See Fig. 4 .
5.7L Component View	In right front corner of intake manifold. See Fig. 5 .
Right side of Firewall	In right front corner of intake manifold. See Fig. 11 .
Engine Speed Sensor (6.2L)	On top center rear of engine.
Knock Sensor (5.7L)
Component Location	On lower right side of engine block, near starter. See Fig. 3 .
Component View	On lower right side of engine block, near starter. See Fig. 5 .
Manifold Absolute Pressure (MAP) Sensor
5.7L Component Location	On bracket over right valve cover. See Fig. 3 .
7.4L Component Location	On bracket over right valve cover. See Fig. 4 .
5.7L Component View	On bracket over right valve cover. See Fig. 5 .
7.4L Component View	On bracket over right valve cover. See Fig. 6 .
6.2L	On left side of firewall.
Oil Pressure Sending Unit/Switch
5.7L	On left rear of block. See Fig. 3 .
6.2L	On left rear of block. See Fig. 10 .
7.4L	On front left side of engine block, near oil pan. See Fig. 4 .
Right Side of Firewall	On front left side of engine block, near oil pan. See Fig. 11 .
Oxygen (O2) Sensor
4.3L	In left exhaust manifold. See Fig. 3 .
5.7L	In left exhaust manifold. See Fig. 4 .
Right Side of Firewall	In left exhaust manifold. See Fig. 11 .
Throttle Position Sensor (TPS)
5.7L Component Location	On throttle body. See Fig. 3 .
7.4L Component Location	On throttle body. See Fig. 4 .
5.7L Component View	On throttle body. See Fig. 5 .
7.4L Component View	On throttle body. See Fig. 6 .
Vehicle Speed Sensor (VSS)
5.7L Engine	Mounted on speedometer. See Fig. 3 .
7.4L Engine	Mounted on speedometer. See Fig. 4 .
Water Sensor (Diesel)	On fuel filter assembly.

GMC Suburban V1500 1990 - MOTORS

GMC Suburban V1500 1990 MOTORS LOCATION

Component	Location
A/C-Heater Blower Motor	On right side of firewall, on evaporator case. See Fig. 1 .
Windshield Wiper Motor	On left side of firewall. See Fig. 11 .

GMC Suburban V1500 1990 - SOLENOIDS & SOLENOID VALVES

GMC Suburban V1500 1990 SOLENOIDS & SOLENOID VALVES LOCATION

Component	Location
Canister Purge Solenoid Valve	In left front corner of engine compartment.
Cold Advance Control (CAC) Solenoid (6.2L)	On injection pump under housing cover.
EGR Solenoid (6.2L)	On top of engine, on bracket over left valve cover. See Fig. 10 .
EGR Vacuum Solenoid (5.7L)
Component Location	On top of engine, on bracket over left valve cover. See Fig. 3 .
Component View	On top of engine, on bracket over left valve cover. See Fig. 5 .
Electric Air Control (EAC) Solenoid
5.7L Component Location	On right front of engine, near air pump. See Fig. 3 .
7.4L Component Location	On right front of engine, near air pump. See Fig. 4 .
5.7L Component View	On right front of engine, near air pump. See Fig. 5 .
7.4L Component View	On right front of engine, near air pump. See Fig. 6 .
Exhaust Pressure Regulator (EPR) Solenoid (6.2L)	On top of engine, on bracket over left valve cover. See Fig. 10 .
Fast Idle Solenoid (6.2L)	On injection pump, under housing cover, on left front of engine.
Fuel Tank Selector Solenoid	On right frame rail, near crossmember.
Idle Air Control (IAC) Valve
5.7L Component Location	On right side of throttle body. See Fig. 3 .
7.4L Component Location	On right side of throttle body. See Fig. 4 .
5.7L Component View	On right side of throttle body. See Fig. 5 .
7.4L Component View	On right side of throttle body. See Fig. 6 .
Shutdown Solenoid (6.2L)	On injection pump, under housing cover.
Torque Converter Clutch (TCC) Solenoid	Inside transmission. See Fig. 3 .

GMC Suburban V1500 1990 - SWITCHES

GMC Suburban V1500 1990 SWITCHES LOCATION

Component	Location
A/C Pressure Cycling Switch	On accumulator.
Aux. Cooling Fan Sw. (7.4L TBI)	On right side of block.
Brake/Stop Light Switch	On brake pedal bracket.
Brake Warning Switch	In hydraulic brake combination valve.
Clutch Switch (Cruise)	On clutch pedal bracket.
Fast/Cold Idle Switch (6.2L)	On right rear of engine.
Glow Plug Inhibit Switch	In water crossover near front of engine.
Metal Temp. Switch (4.8L) (1989 ONLY)	On left front of motor, behind diverter valve.
Parking Brake Switch	On parking brake pedal bracket. See Fig. 7 .
TCC Governor Pressure Switch	In transmission.

GMC Suburban V1500 1990 - MISCELLANEOUS

GMC Suburban V1500 1990 MISCELLANEOUS LOCATION

Component	Location
A/C-Heater Blower Motor
Noise Capacitor	In blower motor power feed line.
Resistors	On evaporator housing, next to blower motor. See Fig. 1 .
ALDL Diagnostic Connector
5.7L	Under left side of dash, below instrument cluster. See Fig. 3 .
7.4L	Under left side of dash, below instrument cluster. See Fig. 4 .
Convenience Center	Behind dash, right of steering column. See Fig. 7 .
Engine Block Heater (6.2L)	On left side of engine block.
Fuel Heater/Water Detector (6.2L)	On firewall, in engine compartment.
Fuel Pump Prime/Test Connector
5.7L	On right side of firewall. See Fig. 3 .
7.4L	On right side of firewall. See Fig. 4 .
Fuel/Water Separator (6.2L)	Behind engine, on firewall.
Vacuum Release Valve (Cruise) (1989 ONLY)	On bracket above brake pedal.