Windshield Wiper Motor Circuit Test
WARNING: This page is about a different car, the 2010 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect KR12B windshield wiper relay.
- Test for less than 5 Ω between the ground circuit terminal 85 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Test for less than 5 Ω between the ground circuit terminal 87A and ground.
- If greater than the specified range, test or replace the X50A underhood fuse block.
- Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 87 and ground.
- If the test lamp does not illuminate, test or replace the X50A underhood fuse block.
- Install a test lamp between the control circuit terminal 86 and ground.
- Command the LOW speed wipers ON and OFF using the S82 windshield wiper/washer switch. The test lamp should turn ON and OFF when changing between the commanded states.
- If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
- If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
- Ignition OFF, disconnect the KR12C windshield wiper speed control relay.
- Test for less than 5 Ω between the control circuit terminal 30 of the KR12B windshield wiper relay and control circuit terminal 30 of the KR12C windshield wiper speed control relay.
- If greater than the specified range, test or replace the X50A underhood fuse block.
- Connect the KR12B windshield wiper relay.
- Test for less than 5 Ω between the control circuit terminal 30 of the KR12C windshield wiper speed control relay and ground.
- If greater than the specified range, test or replace the KR12B windshield wiper relay.
- Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 85 of the KR12C windshield wiper speed control relay and ground.
- If the test lamp does not illuminate, test or replace the X50A underhood fuse block.
- Install a test lamp between the control circuit terminal 30 of the KR12C windshield wiper speed control relay and ground.
- Command the LOW speed wipers ON using the S82 windshield wiper/washer switch. The test lamp should illuminate when commanding the LOW speed wipers ON.
- If the test lamp does not illuminate, replace the KR12B windshield wiper relay.
- Connect a test lamp between control circuit terminal 86 of the KR12C windshield wiper speed control relay and B+.
- Command the HIGH speed wipers ON and OFF using the S82 windshield wiper/washer switch. The test lamp should turn ON and OFF when changing between the commanded states.
- If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K9 BCM.
- If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
- Ignition OFF, connect the KR12C windshield wiper speed control relay and disconnect the X1 harness connector at the M75 windshield wiper motor.
- Test for less than 5 Ω between the ground circuit terminal C and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Connect a test lamp between control circuit terminal E and ground.
- Ignition ON, command the LOW speed wipers ON and OFF using the S82 windshield wiper/washer switch. The test lamp should turn ON and OFF when changing between the commanded states.
- If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the KR12C windshield wiper speed control relay.
- If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the KR12C windshield wiper speed control relay.
- Connect a test lamp between control circuit terminal D and ground.
- Command the HIGH speed wipers ON and OFF using the S82 windshield wiper/washer switch. The test lamp should turn ON and OFF when changing between the commanded states.
- If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the KR12C windshield wiper speed control relay.
- If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the KR12C windshield wiper speed control relay.
- If all circuits test normal, test or replace the M7 windshield wiper motor.