Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector X7 at the appropriate door switch.
- Ignition ON, verify a test lamp does not illuminate between the following circuit terminals and ground:
- Control circuit terminal 1
- Control circuit terminal 2
- If the test lamp illuminates, test the appropriate circuit for a short to voltage.
- Ignition OFF, test for infinite resistance between the following circuits and ground:
- Control circuit terminal 1
- Control circuit terminal 2
- If less than the specified value, test the appropriate circuit for a short to ground. If the circuits test normal, test or replace the rearview mirror motor.
- Test for 5-15 ohms of resistance between the control circuit terminal 1 and the control circuit terminal 2.
- If not within the specified range, test both control circuits for an open/high resistance. If the circuits test normal, test or replace the rearview mirror motor.
- If all circuits test normal, replace the appropriate door switch.