SERVICE MANUAL UPDATE WINDSHIELD WIPER DIAGNOSIS
Models Affected: 1989 GRAND PRIX
Information has been developed to provide complete windshield wiper diagnosis in Section 8A for the following Service Manuals . Note that these pages affect both Standard and Pulse Windshield Wiper Systems.
Year Service Manual Pages ---- -------------- ----- 1989 Pontiac Grand Prix 8A-91-9 through 8A-91-12
SYSTEM DIAGNOSIS
Do the tests listed for your symptom in the Symptom Table below.
Tests follow the Symptom Table.
Refer to 1989 schematic for details.
SYMPTOM TABLE
SYMPTOM DO
---- Wipers cycle in and Replace Park Switch. out of park in OFF refer to Section 8E and operate in I.O
Wipers cycle in and A: Wiper Motor out of park in HI or Assembly Input OFF Voltage Test (Pulse or Standard)
B: Wiper Motor Assembly Resistance Test (Pulse or Standard)
Wipers operate very C: Wiper Motor Assembly slowly or intermittently Current Draw Test
A: WIPER MOTOR ASSEMBLY INPUT VOLTAGE TEST (STANDARD)
Measurs: VOLTAGE
At: WIPER MOTOR ASSEMBLY CONNECTORS C1 & C2 (Disconnected)
Conditions:
- Ignition Switch: ACCY - Wiper Switch: MIST, LO
Measure Correct For Between Voltage Diagnosis ------- ------- --------- GRY & Battery See 1 Ground
GRY & Battery See 2 BLK
DK GRN or Battery See 3 DK GRN/ WHT & Ground
PPL & 0 volts See 4 Ground
- Wiper Switch: OFF
GRY & 0 volts See 4 Ground
DK GRN or Battery See 3 DK GRN/ WHT & Ground
PPL & 0 volts See 4 Ground
- Wiper Switch: HI
GRY & 0 volts See 4 Ground
DK GRN or DK GRN/ 0 volts See 4 WHT & Ground
C2/A (PPL) Battery See 5 & Ground
If all voltages are correct and Wiper Motor does not turn, do test E.
1. Check GRY (91) wire for an open. If OK, replace the Wiper Switch Assembly.
2. Check BLK (150) wire for an open.
3. Check DK GRN or DK GRN/WHT (95) wire for an open. If OK, replace the Wiper Switch Assembly.
4. Replace the Wiper Switch Assembly.
5. Check PPL (92) wire for an open. If OK. replace the Wiper Switch Assembly.
B: WIPER MOTOR ASSEMBLY RESISTANCE TEST (STANDARD)
Measure: RESISTANCE
AT: WIPER MOTOR ASSEMBLY CONNECTORS C1 & C2 (Disconnected)
Conditions:
- Ignition Switch: OFF - Wiper Switch: OFF
Measure Correct For Between Resistance Diagnosis ------- ---------- -------- GRY & DK Infinite See 1 GRN/WHT or DK GRN
YEL & Less than See 2 YEL 0.5 ohm
- Wiper Switch: HI, LO, MIST
GRY & DK Less than See 1 GRN/WHT 0.5 ohm or DK GRN
If all measurements are correct, check for proper operation of Latch Arm and Drive Pawl.
1. Check GRY (91) and DK GRN or DK GRN/WHT (95) wires for shorts to ground, to each other or for opens.
2. Check YEL (196) wire for an open.
A: WIPER MOTOR ASSEMBLY INPUT VOLTAGE TEST (PULSE)
Measure: VOLTAGE
AT: WINDSHIELD WIPER MOTOR ASSEMBLY CONNECTORS C1 & C2 (Disconnected)
Conditions
- Ignition Switch: ACCY - Wiper Switch: OFF
Connect Correct For Between Voltage Diagnosis ------- ------- --------- PPL & 0 volts See 1 Ground
GRY & 0 volts See 1 Ground
DK GRN or Battery See 2 DK GRN/ WHT & Ground
PNK & Battery See 2 Ground
- Wiper Switch: MIST
PPL & 0 volts See 1 Ground GRY & 0 volts See 2 Ground
DK GRN or Battery See 2 DK GRN/ WHT & Ground
PNK & Battery See 2 Ground
- Wiper Switch: PULSE
PPL & 0 volts See 1 Ground
GRY & Battery See 2 Ground
DK GRN or 0 volts See 1 DK GRN/ WHT & Ground
PNK & Battery See 2 Ground
- Wiper Switch: LO
PPL & 0 volts See 1 Ground
GRY & Battery See 2 Ground DK GRN or Battery See 2
DK GRN/ WHT & Ground
PNK & Battery See 2 Ground
- Wiper Switch: HI
PPL & Battery See 2 Ground
GRY & 0 volts See 1 Ground
DK GRN/ 0 volts See 1 WHT or DK GRN & Ground
PNK & Battery See 2 Ground
-Wiper Switch: OFF & Washer Switch ON
PPL & 0 volts See 1 Ground
GRY & Battery See 2 Ground
DK GRN/ Battery See 2 WHT or DK GRN
PNK & Battery See 2 Ground
If all measurements are correct and the Wiper Motor is on all the time, replace the Cover Assembly. Refer to Section 8E. Otherwise return to the Symptom Table.
1. Check associated wiring for a short to voltage. If wiring is good, replace the Wiper/Washer Switch. Refer to Section 3B4.
2. Check associated wiring to the Wiper/Washer Switch for an open or short to ground. If wiring is good, replace the Wiper/Washer Switch. Refer to Section 3B4.
B: WIPER MOTOR ASSEMBLY RESISTANCE TEST (PULSE)
Measure: RESISTANCE
AT: WIPER MOTOR ASSEMBLY CONNECTORS C1 & C2 (Disconnected)
Conditions:
- Ignition Switch: OFF - Wiper Switch: Hi - Negative Battery Terminal (Disconnected)
Measure Correct For Between Resistance Diagnosis ------- ---------- --------- C1/C (DK Less than See 1 GRN) & 0.5 ohms C1/B (GRY)
- Wiper Switch: OFF, PULSE
C1/C (DK Infinite See 1 GRN) & C1/B (GRY)
C1/A (YEL) Less than & C2/B 0.5 ohms See 2 (YEL)
C1/A (YEL) Infinite See 3 & Ground ohms
If all measurements are correct, check for proper operation of the Park Switch Latch Arm and the Drive Pawl.
1. Check DK GRN or DK GRN/WHT (95) and GRY (91) wires for a short to ground, to each other or opens. If wires are OK, replace Wiper Switch Assembly.
2. Repair open in YEL (196) wire.
3. Repair short to ground in YEL (196) wire.
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.
