Wiper Motor Module Current Draw 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.
- Remove wiper fuse. Connect an ammeter (30 amp range or higher) across fuse terminals. Turn ignition switch to RUN position and wiper/washer switch to HI position. Read ammeter, and record lowest reading. If reading is less than 3 amps or cycles between any number and zero, check:
- Motor ground
- Brush/Commutator condition
- Circuit Breaker (should be closed)
- Armature
- If reading is greater than 6.5 amps, replace wiper blades, and repeat current measurement. If reading is less than 6.5 amps, wiper blades were problem. If reading is more than 6.5 amps, disconnect linkage from motor crank, and repeat current measurement.
- If reading is less than 6.5 amps, linkage is binding. Repair as necessary. If reading is more than 6.5 amps, remove wiper motor module, and repair as necessary.