Wiper Motor Module Resistance Test
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 1991 Pontiac Grand Prix, 1991 Pontiac Grand Am, 1991 Pontiac Firebird, 1991 Pontiac Bonneville, and 1991 Pontiac 6000. However, it is still accessible from the selected car via links, so may be relevant.
- Disconnect wiper motor module connectors C1 and C2. Ensure ignition switch is in OFF position and wiper/washer switch is in HI position. Use an ohmmeter to measure resistance between C1 terminal "C" (Dark Green wire) and C1 terminal "B" (Gray wire). If resistance is less than .5 ohms, check park switch latch arm and drive pawl for proper operation.
- If resistance is more than .5 ohms, check circuits No. 95 (Dark Green wire) and No. 91 (Gray wire) for open or short to ground or each other. If wires are okay, replace wiper/washer switch. With ignition off and wiper/washer switch in PULSE position, check resistance between C1 terminal "C" (Dark Green wire) and C1 terminal "B" (Gray wire).
- If ohmmeter reads infinite resistance, check park switch latch arm and drive pawl for proper operation. If reading shows measurable resistance, check circuits No. 95 (Dark Green wire) and No. 91 (Gray wire) for open or short to ground or each other. If wires are okay, replace wiper/washer switch.
- Measure resistance between C1 terminal "A" (Yellow wire) and C2 terminal "B" (Yellow wire). If resistance is .5 ohms or less, check park switch latch arm and drive pawl for proper operation. If ohmmeter shows infinite resistance, check for open circuit No. 196 (Yellow wire).
- Measure resistance between C1 terminal "A" (Yellow wire) and ground. If reading is infinite ohms, check park switch latch arm and drive pawl for proper operation. If reading is measurable resistance, check circuit No. 196 (Yellow wire) for short to ground.