Buick Century Limited 1990 - ELECTRICAL COMPONENT LOCATOR 1989-90 ELECTRICAL COMPONENT LOCATIONS General Motors Corp. - Electrical Components

Buick Century Limited 1990 - BUZZERS, RELAYS & TIMERS

Buick Century Limited 1990 BUZZERS, RELAYS & TIMERS LOCATION

Component	Location
ABS Main Relay (6000 STE)	On bracket, at right front corner of engine compartment. See Fig. 1 .
ABS Pump Motor Relay (6000 STE)	On bracket, at right front corner of engine compartment. See Fig. 1 .
A/C Compressor Control Relay
2.5L	On bracket, at right front corner of engine compartment. See Fig. 2 .
2.8L (1989) & 3.1L	On bracket, at right front corner of engine compartment. See Fig. 3 .
3.3L	On bracket, at right front corner of engine compartment. See Fig. 4 .
A/C-Heater Blower Cut-Out Relay	On bracket, above blower motor.
A/C-Heater Blower Relay
Except 3.3L	On bracket, next to blower motor.
3.3L	On bracket, at right front corner of engine compartment. See Fig. 4 .
Cooling Fan Relay
2.5L	On bracket, at right front corner of engine compartment. See Fig. 2 .
2.8L (1989) & 3.1L	On bracket, at right front corner of engine compartment. See Fig. 3 .
3.3L	On bracket, at right front corner of engine compartment. See Fig. 4 .
Cooling Fan Relay (Pusher Fan)	On bracket, at right front corner of engine compartment. See Fig. 4 .
Defogger Timer Relay	Behind left side of dash, above steering column.
Differential Lock Control Relay	Under center console, behind shifter.
Electronic Level Control Inflator Timer Relay	At left rear corner of luggage compartment.
Electronic Level Control Relay
Sedan	In left side of luggage compartment.
Wagon	On frame, to left of fuel tank.
Fog Light Relay	Behind left side of dash, above ALDL diagnostic connector.
Fuel Pump Relay
2.5L	On bracket, at right front corner of engine compartment. See Fig. 2 .
2.8L (1989) & 3.1L	On bracket, at right front corner of engine compartment. See Fig. 3 .
3.3L	On bracket, at right front corner of engine compartment. See Fig. 4 .
Hazard Flasher Relay	On convenience center.
Horn Relay	On convenience center.
Power Antenna Relay	Near antenna motor.
Power Door Lock Relay	At top of right kick panel.
Rear Wiper Relay	In top center of tailgate.
Tailgate Release Relay	Behind right side of dash, at center of glove box.
Theft Deterrent Relay	Behind dash, strapped to theft deterrent controller.
Timer Delay Relay (6000 STE)	Behind right side of dash, next to ABS module.
Turn Signal Flasher Relay	To right of steering column, clipped to ashtray bracket.

Buick Century Limited 1990 - CIRCUIT PROTECTION DEVICES

Buick Century Limited 1990 CIRCUIT PROTECTION DEVICES LOCATION

Component	Location
ABS Main Relay Fuse (6000 STE)	On bracket, at right front corner of engine compartment. See Fig. 1 .
ABS Pump Motor Relay Fuse (6000 STE)	On bracket, at right front corner of engine compartment. See Fig. 1 .
Battery Junction Block	On right fender panel, in front of canister purge solenoid valve. See Fig. 3 .
Convenience Center	Behind right hand side of instrument panel, near shroud. See Fig. 5 .
Differential Lock Switch/Time Delay Relay Fuse	In convenience center.
Fuel Pump In-Line Fuse	On bracket, at right front corner of engine compartment. See Fig. 3 .
Fuse Block
2.5L	Behind dash, to left of glove box. See Fig. 2 .
2.8L (1989) & 3.1L	Behind dash, to left of glove box. See Fig. 3 .
3.3L	Behind dash, to left of glove box. See Fig. 4 .
Fusible Links
ABS Relays (Rust)	At battery junction block. See Fig. 1 .
A/C-Heater Blower/Fuel Pump Relay (Rust)	At battery junction block.
Alternator (Rust)	At starter solenoid.
Battery Junction Block (Rust)	In harness, near battery.
Cooling Fan Relays (Rust)
Except 6000 STE	At starter solenoid.
6000 STE	At battery junction block.
Ignition Switch (Rust)	In harness, next to battery.
Light Switch (Rust)	In harness, next to battery
Power Accy./Hazard (Rust)	In harness, next to battery.
Lumbar Seat Switch Fuse	In convenience center.
Power Accessory Circuit Breaker	In fuse block.
Power Window Circuit Breaker	In fuse block.
Radio Fuse	In convenience center.
Theft Deterrent In-Line Fuses	Taped to wiring harness under left side of dash.

Buick Century Limited 1990 - CONTROL UNITS

Buick Century Limited 1990 CONTROL UNITS LOCATION

Component	Location
ABS Control Module (6000 STE)	Behind right side of dash, under glove box.
A/C Vacuum Solenoid Module	Behind right side of dash, to left of DIC. See Fig. 5 .
Audio Alarm Module	In convenience center.
Cruise Control Module	Behind dash, above accelerator pedal.
C(3)I Module (3.3L)	At left front of engine. See Fig. 4 .
Daytime Running Lights (DRL) Module	Behind right side of dash, to right of glove box.
Driver Information Center (DIC) Module	Behind center of dash. See Fig. 5 .
Distributorless Ignition (DIS) Module
2.5L	At right rear corner of engine block. See Fig. 2 .
2.8L (1989) & 3.1L	On left side of engine block, behind A/C compressor. See Fig. 6 .
Electronic Control Module (ECM)
2.5L	Behind dash, to left of glove box. See Fig. 2 .
2.8L (1989) & 3.1L	Behind dash, to left of glove box. See Fig. 3 .
3.3L	Behind dash, to left of glove box. See Fig. 4 .
Low Coolant Module	Taped to harness, to left of fuse block.
Park/Turn Lamp Module	Behind right hand side of instrument panel, near fuse block.
Passive Restraint Module	On right hand shroud.
Theft Deterrent Controller	Behind dash, below light switch.

Buick Century Limited 1990 - SENDING UNITS & SENSORS

Buick Century Limited 1990 SENDING UNITS & SENSORS LOCATION

Component	Location
ABS Speed Sensors (6000 STE)	At each wheel.
Coolant Temperature Sensor (CTS)
2.5L	At rear of engine, in coolant outlet. See Fig. 2 .
2.8L (1989) & 3.1L	At left rear corner of intake manifold. See Fig. 3 .
3.3L	Under Alternator, to right of coolant temperature sending unit. See Fig. 4 .
Coolant Temp. Sending Unit/Switch
2.5L	In cylinder head, in front of coolant outlet.
2.8L & 3.1L	At right rear corner of cylinder head.
3.3L	Under alternator, to left of CTS.
Crankshaft Sensor
2.8L (1989) & 3.1L (1989)	On right side of engine block. See Fig. 3 .
3.3L	On right side of engine block. See Fig. 4 .
Dual Crank Sensor (1990)	On right side of engine block. See Fig. 4 .
Electronic Level Cont. Height Sensor
Sedan	On rear frame, near right rear shock.
Wagon	On rear frame, in front of fuel tank.
Fuel Gauge Sending Unit	In fuel tank.
Knock Sensor
2.8L (1989) & 3.1L	On right front side of engine block. See Fig. 3 .
3.3L	On right front side of engine block. See Fig. 4 .
Man. Absolute Press. (MAP) Sensor
2.5L	On right side of air cleaner. See Fig. 2 .
2.8L (1989) & 3.1L	On valve cover bracket, behind alternator. See Fig. 3 .
Man. Air Temp. (MAT) Sensor
2.5L	In intake runner, in front of throttle body. See Fig. 2 .
2.8L (1989) & 3.1L	In air cleaner housing. See Fig. 3 .
Mass Airflow (MAF) Sensor (3.3L)	On throttle body. See Fig. 4 .
Oil Press. Sending Unit/Switch
2.5L	On rear of engine, to right of distributor.
2.8L (1989) & 3.1L	On left front side of engine, above oil filter.
3.3L	On right side of engine, to left of harmonic balancer.
Oxygen Sensor
2.5L	In exhaust manifold. See Fig. 2 .
2.8L (1989) & 3.1L	In exhaust manifold. See Fig. 3 .
3.3L	In exhaust manifold. See Fig. 4 .
Throttle Position Sensor (TPS)
2.5L	On throttle body. See Fig. 2 .
2.8L (1989) & 3.1L	On throttle body. See Fig. 3 .
3.3L	On throttle body. See Fig. 4 .
Vehicle Speed Sensor (VSS)
2.5L	On top right side of transaxle. See Fig. 2 .
2.8L (1989) & 3.1L	On top right side of transaxle. See Fig. 3 .
3.3L	On top right side of transaxle. See Fig. 4 .

Buick Century Limited 1990 - MOTORS

Buick Century Limited 1990 MOTORS LOCATION

Component	Location
ABS Pump Motor (6000 STE)	Below master cylinder assembly.
A/C-Heater Blower Motor	On right side of engine compartment.
Elect. Level Control Compressor	On frame, behind left rear wheelwell.
Idle Air Control (IAC) Motor
2.5L	On throttle body. See Fig. 2 .
2.8L (1989) & 3.1L	On throttle body. See Fig. 3 .
3.3L	On throttle body. See Fig. 4 .
Power Antenna Motor	On rail assembly, at base of antenna.
Power Door Lock Motor	Near lower rear portion of each door.
Power Mirror Motor	In each mirror assembly.
Power Seat Motor	Under seat assembly.
Power Window Motor	In each door.
Rear Washer Motor	On right front fender panel, in front of shock tower.
Rear Wiper Motor	In top center of tailgate.
Sun Roof Motor	In windshield header, in front of sun roof.
Windshield Wiper/Washer Motor	On upper left side of engine compartment.

Buick Century Limited 1990 - SOLENOIDS & SOLENOID VALVES

Buick Century Limited 1990 SOLENOIDS & SOLENOID VALVES LOCATION

Component	Location
ABS Main Valve (6000 STE)	On front of master cylinder assembly.
ABS Valve Block (6000 STE)	On right side of master cylinder assembly.
Canister Purge Solenoid Valve
2.8L (1989) & 3.1L	On vapor canister. See Fig. 3 .
3.3L	On vapor canister. See Fig. 4 .
Differential Lock Vacuum Solenoid	At right front of engine, in front of knock sensor.

Buick Century Limited 1990 - SWITCHES

Buick Century Limited 1990 SWITCHES LOCATION

Component	Location
ABS Pressure Switch (6000 STE)	On front of master cylinder assembly, below main valve.
A/C High Pressure Cut-Out Switch	At rear of compressor. See Fig. 3 .
A/C Low Pressure Cut-Out Switch	At rear of compressor. See Fig. 3 .
A/C Pressure Cycling Switch	On right side of engine compartment, near accumulator.
A/C Pressure Fan Switch	In refrigerant line near compressor. See Fig. 3 .
Ajar Switches (6000 STE)	One at each door jamb, hood and luggage compartment.
Brake/Cruise/TCC Switch	On brake pedal support.
Brake Fluid Level Sw. (6000 STE)	In brake fluid reservoir cap.
Brake Pressure Switch	Below left side of brake fluid reservoir.
Clutch Switch	On brake pedal support.
Differential Lock Engagement Switch	On right of transaxle, just below exhaust manifold outlet.
Elect. Level Control Inflator Switch	At left rear of luggage compartment.
Lugg. Comp. Lid Tamper Switch	In luggage compartment lid, near lock assembly.
Parking Brake Switch	On parking brake assembly.
Park/Neutral Switch
2.5L	On top left side of transaxle. See Fig. 2 .
2.8L (1989) & 3.1L	On top left side of transaxle. See Fig. 3 .
3.3L	On top left side of transaxle. See Fig. 4 .
Power Steering Press. Switch (PSPS)
2.5L	In power steering fluid line, near power steering pump. See Fig. 2 .
2.8L (1989) & 3.1L	In power steering fluid line, near power steering pump. See Fig. 3 .
3.3L	In power steering fluid line, near power steering pump. See Fig. 4 .

Buick Century Limited 1990 - MISCELLANEOUS

Buick Century Limited 1990 MISCELLANEOUS LOCATION

Component	Location
ABS Diode (6000 STE)	Behind right side of dash, taped to wiring harness. See Fig. 5 .
A/C Compressor Diode
Celebrity	In engine harness, near compressor.
All But Celebrity	In compressor wiring connector.
A/C-Heater Blower Resistors	On right side of engine cowl.
ALDL Diagnostic Connector
2.5L	On bottom of dash, near steering column. See Fig. 2 .
2.8L (1989) & 3.1L	On bottom of dash, near steering column. See Fig. 3 .
3.3L	On bottom of dash, near steering column. See Fig. 4 .
Cooling Fan Relay Diode (3.3L)	In wiring harness, near cooling fan relay.
Fuel Pump Prime/Test Connector
2.5L	In front of transaxle, clipped to harness. See Fig. 2 .
2.8L (1989) & 3.1L	In wiring harness, near fuel pump relay. See Fig. 3 .
3.3L	In wiring harness, below manifold air temperature sensor. See Fig. 4 .
Vehicle Speed Sensor Buffer
2.5L (1989)	Behind right side of dash, behind ECM. See Fig. 2 .
3.3L	Behind right side of dash, behind ECM. See Fig. 4 .