GMC Suburban V2500 1991 - ELECTRICAL COMPONENT LOCATOR 1991 GENERAL MOTORS TRUCKS ELECTRONIC COMPONENT LOCATOR

GMC Suburban V2500 1991 - BUZZERS, RELAYS & TIMERS

GMC Suburban V2500 1991 BUZZERS, RELAYS & TIMERS LOCATION

Component	Location
A/C-Heater Blower Relay	On evaporator case, on right side of firewall. See Fig. 1 .
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. See Fig. 2 .
Fuel Pump Relay
5.7L Shown, 5.0L Similar	On right side of firewall, on relay block. See Fig. 3 .
7.4L	On right side of firewall, on relay block. See Fig. 4 .
Hazard Flasher Relay	On convenience center. See Fig. 5 .
Horn Relay
Under Dash	On convenience center. See Fig. 5 .
From Behind Dash	On convenience center. See Fig. 6 .
Power Door Lock Relay	Behind dash, on left side of brake pedal support. See Fig. 7 .
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. See Fig. 5 .

GMC Suburban V2500 1991 CIRCUIT PROTECTION DEVICES LOCATION

Component	Location
Circuit Breakers	In fuse block.
Fuse Block
5.7L Shown, 5.0L Similar	Under left side of dash. See Fig. 3 .
7.4L	Under left side of dash. See Fig. 4 .

GMC Suburban V2500 1991 CONTROL UNITS LOCATION

Component	Location
Cruise Control Module	On right side of steering column support. See Fig. 8 .
Diesel Elec. Control (DEC) Module	Right side of dash. See Fig. 2 .
DRAC Module	Behind left side of dash, right of steering column.
Electronic Control Module (ECM)
5.7L Shown, 5.0L Similar	Under right side of dash. See Fig. 3 .
7.4L	Under right side of dash. See Fig. 4 .
Electric Brake Module	On firewall, left of master cylinder.
Elec. Spark Control (ESC) Module
5.7L Shown, 5.0L Similar	On top right side of engine. See Fig. 3 .
7.4L	On top right side of engine. See Fig. 4 .
Fuel Pump Module (5.7L H/D)	Under left side of dash. See Fig. 3 .
Glow Plug Controller (6.2L)	On rear of left cylinder head.
Windshield Wiper Delay Module	On bottom of steering column.

GMC Suburban V2500 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
5.0L, 5.7L & 6.2L	On front of left cylinder head.
7.4L	On right or left cylinder head, above exhaust manifold.
Coolant Temperature Sensor (CTS)
5.7L Shown, 5.0L Similar	In right front corner of intake manifold. See Fig. 3 .
7.4L	In right front corner of intake manifold. See Fig. 4 .
Engine Speed Sensor (6.2L)	On top center rear of engine. See Fig. 2 .
Knock Sensor
5.7L Shown, 5.0L Similar	On lower right side of engine block, near starter. See Fig. 3 .
7.4L	On lower right side of engine block, near starter. See Fig. 4 .
Manifold Absolute Pressure (MAP) Sensor
5.7L Shown, 5.0L Similar	On bracket over right valve cover. See Fig. 3 .
7.4L	On bracket over right valve cover. See Fig. 4 .
6.2L	On left side of firewall. See Fig. 2 .
Oil Pressure Sending Unit/Switch
5.0L, 5.7L	On left rear of block. See Fig. 3 .
6.2L	On left rear of block.
7.4L	On front left side of engine block, near oil pan. See Fig. 4 .
Throttle Position Sensor (TPS)
5.7L Shown, 5.0L Similar	On throttle body. See Fig. 3 .
7.4L	On throttle body. See Fig. 4 .
6.2L Diesel	On throttle body. See Fig. 2 .
Vehicle Speed Sensor (VSS)
5.7L Shown, 5.0L Similar	Mounted on transmission tailshaft. See Fig. 3 .
7.4L	Mounted on transmission tailshaft. See Fig. 4 .
Water Sensor (Diesel)	On fuel filter assembly.

GMC Suburban V2500 1991 MOTORS LOCATION

Component	Location
A/C-Heater Blower Motor	On right side of firewall, on evaporator case. See Fig. 1 .
Door Lock	In bottom of respective door.
Idle Air Control (IAC) Motor
5.7L Shown, 5.0L Similar	On right side of throttle body. See Fig. 3 .
7.4L	On right side of throttle body. See Fig. 4 .
Windshield Wiper Motor	On left side of firewall.

GMC Suburban V2500 1991 SOLENOIDS & SOLENOID VALVES LOCATION

Component	Location
Cold Advance Control (CAC) Solenoid (6.2L)	On injection pump under housing cover.
EGR Solenoid (6.2L)	On top of engine, on bracket above left valve cover. See Fig. 2 .
EGR Vacuum Solenoid
5.7L Shown, 5.0L Similar	On top of engine, on bracket above left valve cover. See Fig. 3 .
7.4L	On top of engine, on bracket above left valve cover. See Fig. 4 .
EGR Vent Solenoid (6.6L)	On top of engine, on bracket above left valve cover. See Fig. 2 .
Electric Air Control (EAC) Solenoid	On right front of engine, near air pump. See Fig. 4 .
Exhaust Pressure Regulator (EPR) Solenoid (6.2L)	On top of engine, on bracket over left valve cover. See Fig. 2 .
Fast Idle Solenoid (6.2L)	On injection pump, under housing cover, on left front of engine. See Fig. 2 .
Fuel Tank Selector Solenoid	On right frame rail, near crossmember.
Shutdown Solenoid (6.2L)	On injection pump, under housing cover.
Torque Converter Clutch
5.7L Shown, 5.0L Similar	Inside transmission. See Fig. 3 .
6.2L Diesel	Inside transmission. See Fig. 2 .

GMC Suburban V2500 1991 SWITCHES LOCATION

Component	Location
A/C Pressure Cycling Switch	On accumulator. See Fig. 1 .
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.
Parking Brake Switch	On parking brake pedal bracket. See Fig. 6 .
TCC Governor Pressure Switch	In transmission.

GMC Suburban V2500 1991 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 Shown, 5.0L Similar	Under left side of dash, below instrument cluster. See Fig. 3 .
7.4L	Under left side of dash, below instrument cluster. See Fig. 4 .
6.2L Diesel	Under left side of dash, below instrument cluster. See Fig. 2 .
Convenience Center
Under Dash	Behind dash, right of steering column. See Fig. 5 .
From Behind Dash	Behind dash, right of steering column. See Fig. 6 .
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 Shown, 5.0L Similar	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 Pump (6.2L)	On top center rear of engine. See Fig. 2 .