SERVICE MANUAL UPDATE SEC.8A- ELECTRICAL DIAGNOSIS

MODELS AFFECTED: 1989 SKYHAWK

The following pages reflect product changes. These pages are as follows:

8A-1-0 INDEX

8A-1-1 INDEX

8A-11-6-A FUSE BLOCK DETAILS: INST LPS Fuse

8A-14-0-A GROUND DISTRIBUTION: G100, G101, G115, AND G200 INSTRUMENT PANEL GROUND

8A-117-1-A INTERIOR LIGHT DIMMING

8A-201-11 COMPONENT LOCATION VIEWS

8A-201-11A COMPONENT LOCATION VIEWS

In addition, the following pages should be revised to reflect minor changes for late production, as noted:

8A-34-0 Change the .5 BRN (986) wire from the Brake Switch to .5 BRN/WHT (379)

8A-34-0 Change the .5 BRN/WHT (986) wire from the Cruise Control Clutch Switch to .5 BRN/WHT (379)

8A-34-0 Change the BRN and BRN/WHT (986) wire in the Check Brake System Test to BRN/WHT (379) wire

8A-34-10 See Update Change for page 8A-34-4

8A-41-0 Delete connector C206 (AUTOMATIC) C270 (MANUAL) from the wire running between splice S232 and the Park Brake Switch. The wire color and gage is .8 TAN/WHT.

8A-134-1 Delete connector C270 from the wire running between splice S232 and the Park Brake Switch. The wire color and gage is .8 TAN/WHT.

Chassis Service Page/Revision Manual Page and Category Air Conditioning ------------ ------------- Air Delivery Manual................................65-0 Blower Controls Manual................................63-0 Compressor Controls Manual................................64-0 System Check.............................62-0 Alarms (Audible) Chime...................................76-0 Antenna (Power)......................... 151-0 Brakes Warning System.................... 41-0 ............ 41-0 3 Charging System ..................... 30-0 Circuit Breaker Details..............10-1,11-0 Clock (Digital)..........................150-0 Component Location Views................ 201-0 ......... 201-11-A 1, 201-11 2 Connectors (Harness Connector Faces)..... 202-0 Coolant Fan .............................. 31-0 Coolant Temperature Gage.................. 81-2 Cruise Control.............................34-0 .....34-0 3, 34-4 3, 34-10 3 Defogger(Rear)............................ 61-0 Digital Clock............................ 150-0 Door Locks (Power)....................... 130-0 Engine Control Throttle Body Injection (L4 VIN 1)...... 21-0 Fuse Block Details ....................... 11-0 ............11-6-A 1 Fuse Details......................... 10-0,11-0 ............11-6-A 1 Fusible Link Details ..................... 10-0 Gages Gages Cluster........................... 81-0 Coolant Temperature.................. 81-2 Fuel..................................81-2 Oil Pressure......................... 81-2 Tachometer............................81-2 Voltmeter............................ 81-2 Standard Cluster ......................... 80-0 Fuel............................... 80-1

Ground Distribution........................14-0 ............14-0-A 1 Harness Routing Views.................... 203-0 Heater.................................... 60-0 Horns..................................... 40-0 Gages Cluster ......................... 81-0 Brake ................................81-0 Charge................................81-0 Cruise................................81-0 Fasten Belts. ........................81-1 Hi Beam.............................. 81-1 LH Turn...............................81-1 RH Turn...............................81-1 Service Engine Soon ..................81-0 Shift.................................81-0 Tailgate Ajar .......................81-0 Standard Cluster.........................80-0 Brake ................................80-0 Charge................................80-0 Cruise................................80-0 Fasten Belts......................... 80-1 Hi Beam...............................80-1 LH Turn ............................. 80-1 Oil...................................80-0 RH Turn...............................80-1 Service Engine Soon...................80-0 Shift.................................80-0 Tailgate Ajar ........................80-0 Temp .............................. 80-0 Instrument Panel Gages Cluster ......................... 81-0 Standard Cluster.........................80-0 Interior Lights Dimming ................. 117-0 ...........117-1-A 1 Introduction.............................. 2-0 Lights (Exterior) Back Up ............................... 112-0 Fog.....................................100-1 Front Marker .......................... 110-0 Front Park..............................110-0 Hazard................................. 110-0 Headlights..............................100-2

Doors.................................. 102-0 High Level Stop ....................... 110-3 License...................................110-4 Park....................................110-0 Rear Marker............................ 110-4 Stop ...................................110-1 Tail................................... 110-1 Turn....................................110-0 Lights (Interior) Ashtray................................ 117-1............117-1-A 1 Cargo.................................. 114-0 Courtesy................................114-0 Dome .................................. 114-0 Fiber Optic Light Source................117-1 Heater and A/C Control Assembly ........117-1 Instrument Cluster......................117-1 I/P Compartment........................ 114-1 PRNDL.................................. 117-1 ...........117-1-A 1 Radio ................................. 114-1 Reading................................ 114-0 Rear Compartment........................114-1 Rear Defogger Control ..................117-1 Underhood ..............................110-0 Light Switch Details...................... 12-0 Luggage Compartment Lid Release ..........134-0 ...........134-1 3 Oil Pressure Gage..........................81-2 Power Door Locks..........................130-0 Power Windows.............................120-0 Radio.....................................150-0 Rear Defogger..............................61-0 Repair Procedures.......................... 5-0 Starter....................................30-0 Symbols.................................... 3-0 Tachometer................................ 81-2 Tailgate Release..........................134-1 .......... 134-1 3 Troubleshooting Procedures................. 4-0 Vehicle Speed Sensor.......................33-0 Voltmeter................................. 81-2 Warnings (Audible) Chime.................................. 76-0 Windows (Power)...........................120-0 Wiper/Washer With Pulse.............................. 91-0 Standard.................................90-0

KEY 1 -Late Production 2 -Revised 3 - Refer to Update Change Summary on following page

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.