Installation Troubleshooting for Rear Wiper Controller

Supplies Needed

• Volt/Ohm meter

Step-by-Step Instructions

1. Select the voltage measurement mode on your meter. Connect the negative lead of the meter to an appropriate ground point on the car, and touch the positive lead to the contact for the yellow wire on the WCU harness. This wire should read 0V when the car is off, and 12V when the car is on (position II on the ignition).

If this test fails: Check the under-dash fuse panel. The number 15 (10A) fuse may be blown.



2. Select the continuity test or resistance measurement mode on your meter. Connect the negative lead of the meter to an appropriate ground point on the car, and touch the positive lead to the contact for the black wire on the WCU harness. This wire should have infinite resistance when the rear wiper switch is off, and 0 ohms when on.

If this test fails: Check that the black wire is connected to the car's solid dark green wire, on the side coming from the connector.



3. Select the voltage measurement mode on your meter. Connect the negative lead of the meter to an appropriate ground point on the car, and touch the positive lead to the contact for the red wire on the WCU harness. This wire should read 0V when the car is off, and 12V when the car is on (position II on the ignition).

If this test fails: Check that the red wire is connected to the car's solid dark green wire, on the side coming from the harness.



4. Select the voltage measurement mode on your meter. Connect the negative lead of the meter to an appropriate ground point on the car, and touch the positive lead to the contact for the purple wire on the WCU harness. Start the car, and with a friend's help, drive very slowly in any direction (in your driveway should be fine) and verify that the reading switches between 0V to 12V as the car moves.

If this test fails: Check that the speedometer works properly. If so, check that the WCU purple wire is connected to the car's orange wire in the MRU harness.



5. Select the continuity test or resistance measurement mode on your meter. Connect the negative lead of the meter to an appropriate ground point on the car, and touch the positive lead to the contact for the green wire on the WCU harness. This wire should read infinite resistance.

If this test fails: Check that the green wire is connected to the car's light green with black stripe wire.



6. Select the continuity test or resistance measurement mode on your meter. Touch the negative lead of the meter to the green wire on the WCU harness, and touch the positive lead to the black wire on the WCU harness. With the wiper switch in the OFF position, the meter should read 0 ohms.

If this test fails: Check that the green wire is connected to the car's light green with black stripe wire, and that the WCU harness black wire is connected to the car's solid dark green wire, on the side coming from the connector.