Chevrolet Pickup V3500 1991 - ELECTRICAL COMPONENT LOCATOR 1991 ELECTRICAL COMPONENT LOCATIONS General Motors Corp. - Electrical Components

Chevrolet Pickup V3500 1991 - BUZZERS, RELAYS & TIMERS

Chevrolet Pickup V3500 1991 BUZZERS, RELAYS & TIMERS LOCATION

Component	Location
A/C Clutch Relay	On top of plenum, behind right side of dash. See Fig. 1 .
A/C-Heater Blower Relay Nos. 1 & 2	On top of plenum, behind right side of dash. See Fig. 1 .
Auxiliary Battery Relay	On left front inner fender panel, above wheelwell.
Auxiliary Cooling Fan Relay	On left front inner fender panel, near firewall.
Cold Advance Relay (6.2L)
6.2L Diesel Engine	On right side of firewall, behind battery junction block cover. See Fig. 2 .
Firewall	On right side of firewall, behind battery junction block cover. See Fig. 3 .
Flight Relay	Behind dash, above convenience center, next to hazard flasher. See Fig. 4 .
Fuel Pump Relay
4.3L Engine	On right side of firewall, behind battery junction block cover. See Fig. 5 .
5.0L & 5.7L Engines	On right side of firewall, behind battery junction block cover. See Fig. 6 .
7.4L Engine	On right side of firewall, behind battery junction block cover. See Fig. 7 .
Firewall	On right side of firewall, behind battery junction block cover. See Fig. 3 .
Glow Plug Controller Relay	On top of engine, above right valve cover.
Hazard Flasher Relay	Under left side of dash, near convenience center.
Headlight Relay	Behind left side of dash, above convenience center. See Fig. 4 .
Transfer Case Relay	On right side of firewall, behind battery junction block cover.
Transmission Relay	On right side of firewall, behind battery junction block cover. See Fig. 3 .
Turn Signal Flasher Relay	On convenience center.

Chevrolet Pickup V3500 1991 - CIRCUIT PROTECTION DEVICES

Chevrolet Pickup V3500 1991 CIRCUIT PROTECTION DEVICES LOCATION

Component	Location
Circuit Breakers
Accessory/Battery	On fuse block.
Accessory/Ignition	On fuse block.
Fuel Pump In-Line Fuse (5.0L & 5.7L)	On right side of firewall, behind battery junction block cover. See Fig. 6 .
Firewall	On right side of firewall, behind battery junction block cover. See Fig. 3 .
Fuse Block
4.3L Engine	Under left side of dash, near kick panel. See Fig. 5 .
5.0L & 5.7L Engines	Under left side of dash, near kick panel. See Fig. 6 .
7.4L Engine	Under left side of dash, near kick panel. See Fig. 7 .
Fusible Links
A/C (Rust)	On right side of firewall, at battery junction block. See Fig. 3 .
A/T Kickdown Sol. (Red)	On right side of firewall, at battery junction block. See Fig. 3 .
Charging System (Blue)	On right side of firewall, at battery junction block. See Fig. 3 .
Diesel ECM (Gray)	On right side of firewall, at battery junction block. See Fig. 3 .
ECM (Gray)	On right side of firewall, at battery junction block. See Fig. 3 .
Fuse Block (Black)	On right side of firewall, at battery junction block. See Fig. 3 .
Glow Plug Controller (Blue)	On right side of firewall, at battery junction block. See Fig. 3 .
Instrument Panel (Black)	On right side of firewall, at battery junction block. See Fig. 3 .
Junction Block (Diesel) (Blue)	On positive battery cable, below battery.
Junction Block (Gas) (Red)	On positive battery cable, below battery.

Chevrolet Pickup V3500 1991 - CONTROL UNITS

Chevrolet Pickup V3500 1991 CONTROL UNITS LOCATION

Component	Location
Check Engine Light
Driver Module	Under right side of dash, above blower motor. See Fig. 8 .
Cruise Control Module	On left side of firewall, near brake booster. See Fig. 9 .
Electronic Control Module (ECM)
4.3L Engine	Behind right side of dash, above blower motor. See Fig. 5 .
5.0L & 5.7L Engines	Behind right side of dash, above blower motor. See Fig. 6 .
7.4L Engine	Behind right side of dash, above blower motor. See Fig. 7 .
Electronic Spark Control (ESC)
4.3L Engine	On right side of engine, above valve cover. See Fig. 5 .
5.0L & 5.7L Engines	On right side of engine, above valve cover. See Fig. 6 .
7.4L Engine	On right side of engine, above valve cover. See Fig. 7 .
Diesel Electronic Control (DEC) Module	Behind right side of dash, above blower motor. See Fig. 2 .
Glow Plug Controller (6.2L)	On left rear of intake manifold.
Hot Fuel Handling Module	Under ECM, above blower motor. See Fig. 10 .
Low Coolant Module (6.2L)	On center of firewall.
Rear Anti-Lock Brake Module	On bracket, left of master cylinder. See Fig. 9 .
RABS Diode Module	At PCM. See Fig. 10 .

Chevrolet Pickup V3500 1991 - SENDING UNITS & SENSORS

Chevrolet Pickup V3500 1991 SENDING UNITS & SENSORS LOCATION

Component	Location
Cold Advance Control (CAC) & Fast Idle Solenoid Temp. Sensor (6.2L)	On rear of right cylinder head.
Coolant Temp. Sending Unit/Switch	In left cylinder head.
Coolant Temperature Sensor
4.3L	In front of intake manifold, at thermostat housing. See Fig. 5 .
5.0L & 5.7L	On right front of engine, in front of valve cover. See Fig. 6 .
6.2L	On right front of intake manifold.
7.4L	On right front of intake manifold, near thermostat housing. See Fig. 7 .
Engine Speed Sensor (6.2L)	On rear of intake manifold. See Fig. 2 .
Knock Sensor
4.3L Engine	On lower left side of engine, under exhaust manifold. See Fig. 5 .
5.0L & 5.7L Engines	On lower right side of engine, under exhaust manifold. See Fig. 6 .
7.4L Engine	On lower right side of engine, under exhaust manifold. See Fig. 7 .
Manifold Abs. Press. (MAP) Sensor
Diesel	On left side of firewall, near wiper motor. See Fig. 2 .
Gas
4.3L Engine	On right side of engine, above valve cover. See Fig. 5 .
5.0L & 5.7L Engines	On right side of engine, above valve cover. See Fig. 6 .
7.4L Engine	On right side of engine, above valve cover. See Fig. 7 .
Oil Pressure Switch
Diesel	On left rear of engine.
Gas
4.3L Engine	On left side of engine, under exhaust manifold. See Fig. 5 .
5.0L & 5.7L Engines	On left side of engine, under exhaust manifold. See Fig. 6 .
7.4L Engine	On left side of engine, under exhaust manifold. See Fig. 7 .
Throttle Position Sensor (TPS)
Diesel	On injection pump throttle valve. See Fig. 2 .
Gasoline
4.3L Engine	On throttle body. See Fig. 5 .
5.0L & 5.7L Engines	On throttle body. See Fig. 6 .
7.4L Engine	On throttle body. See Fig. 7 .
Vehicle Speed Sensor (VSS)
4.3L Engine	On right side of extension housing (2WD) or transfer case (4WD). See Fig. 5 .
5.0L & 5.7L Engines	On right side of extension housing (2WD) or transfer case (4WD). See Fig. 6 .
7.4L Engine	On right side of extension housing (2WD) or transfer case (4WD). See Fig. 7 .

Chevrolet Pickup V3500 1991 - MOTORS

Chevrolet Pickup V3500 1991 MOTORS LOCATION

Component	Location
A/C-Heater Blower Motor	Behind right side of dash. See Fig. 1 .
A/C-Heater Door Motor	On plenum, behind right side of dash.
Windshield Wiper Motor	In plenum, on left center of firewall.

Chevrolet Pickup V3500 1991 - SOLENOIDS & SOLENOID VALVES

Chevrolet Pickup V3500 1991 SOLENOIDS & SOLENOID VALVES LOCATION

Component	Location
A/T Downshift Solenoid	On left side of transmission, in front of vehicle speed sensor.
Cold Advance Solenoid (6.2L)	On injection pump, on left front of engine.
EGR Vacuum Solenoid
4.3L Engine	On right side of engine, above valve cover. See Fig. 5 .
5.0L & 5.7L Engines	On right side of engine, above valve cover. See Fig. 6 .
6.2L	On top left of engine, near left valve cover. See Fig. 2 .
7.4L	On top of engine, near right valve cover. See Fig. 7 .
EGR Vent Solenoid (6.2L)	On top of engine, near left valve cover. See Fig. 2 .
Elec. Air Control (EAC) Solenoid
4.3L Engine	On right front of engine, near air pump. See Fig. 5 .
5.0L & 5.7L Engines	On right front of engine, near air pump. See Fig. 6 .
7.4L Engine	On right front of engine, near air pump. See Fig. 7 .
Exhaust Pressure Regulator (EPR) Solenoid Valve (6.2L)	On top left rear of engine. See Fig. 2 .
Fast Idle Solenoid (6.2L)	On injection pump, on left front of engine. See Fig. 2 .
Front Axle Solenoid	On right side of differential case.
Fuel Shutoff Solenoid (6.2L)	On injection pump, on left front of engine.
Idle Air Control (IAC) Valve
4.3L Engine	On right side of throttle body. See Fig. 5 .
5.0L & 5.7L Engines	On right side of throttle body. See Fig. 6 .
7.4L Engine	On right side of throttle body. See Fig. 7 .
Rear Anti-Lock Brake Valve	Below master cylinder. See Fig. 9 .
Torque Conv. Clutch (TCC) Solenoid
4.3L Engine	In automatic transmission. See Fig. 5 .
5.0L & 5.7L Engines	In automatic transmission. See Fig. 6 .
6.2L Diesel Engine	In automatic transmission. See Fig. 2 .

Chevrolet Pickup V3500 1991 - SWITCHES

Chevrolet Pickup V3500 1991 SWITCHES LOCATION

Component	Location
A/C Air Inlet Press. Switch	On rear of A/C compressor.
A/C Pressure Cycling Switch	On accumulator.
Back-Up Light Switch (M/T)	On left side of transmission.
Brake Pressure (Warning) Switch	In hydraulic brake combination valve.
Brake/Stoplight Switch	On brake pedal bracket.
Clutch/Neutral Safety Switch	On clutch pedal bracket.
Cooling Fan Temp. Switch (7.4L)	In right cylinder head, above exhaust manifold.
Cruise Control Release Switch	On brake pedal bracket.
Front Axle Switch	Near differential case, at front of engine.
Fuel Pump/Oil Pressure Switch
4.3L	On left rear of engine, near distributor. See Fig. 5 .
5.0L & 5.7L	On left rear of engine block. See Fig. 6 .
7.4L	On left side of engine block, under exhaust manifold. See Fig. 7 .
Headlight Dimmer Switch	On left side of steering column, behind dash.
Inhibit Switch	On right side of firewall, near accumulator.
Low Coolant Switch	On top of radiator.
Parking Brake Switch	On parking brake pedal bracket.
Park/Neutral (P/N) Switch	On steering column, under dash.
TCC Brake Switch	On brake pedal bracket.
TCC Governor Pressure Switch	In automatic transmission.
Transfer Case Switch	On left front of transfer case.

Chevrolet Pickup V3500 1991 - MISCELLANEOUS

Chevrolet Pickup V3500 1991 MISCELLANEOUS LOCATION

Component	Location
A/C Compressor Clutch Diode	In A/C compressor clutch connector.
A/C-Heater Blower Resistor	On evaporator case. See Fig. 1 .
ALDL Diagnostic Connector
4.3L Engine	Under left side of dash, to left of column. See Fig. 5 .
5.0L & 5.7L Engines	Under left side of dash, to left of column. See Fig. 6 .
7.4L Engine	Under left side of dash, to left of column. See Fig. 7 .
6.2L Diesel Engine	Under left side of dash, to left of column. See Fig. 2 .
Battery Junction Block	On right side of firewall, behind cover. See Fig. 3 .
Convenience Center	Under left side of dash, left of steering column. See Fig. 4 .
Fuel Heater/Water Detector (6.2L)	On top right side of engine.
Fuel Pump	In fuel tank (gas) or on left frame rail (diesel).
Fuel Pump Prime/Test Connector
4.3L Engine	On right side of firewall, near battery junction block. See Fig. 5 .
5.0L & 5.7L Engines	On right side of firewall, near battery junction block. See Fig. 6 .
7.4L Engine	On right side of firewall, near battery junction block. See Fig. 7 .