Mirrors: Testing and Inspection

POWER MIRRORS INOPERATIVE

DIAGNOSTIC FAULT INFORMATION




Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

CIRCUIT/SYSTEM DESCRIPTION
The outside rearview mirror switch supplies both voltage and ground to the outside rearview mirror motors. When the outside rearview mirror switch is being pressed the switch supplies the voltage and ground to the proper circuits to engage the proper mirror motor.

DIAGNOSTIC AIDS
- The rearview mirror motors have circuit breakers installed in the motors. The circuit breakers will open the circuit after 30 seconds of continuous voltage.
- The rearview mirror motors are bi-directional. When voltage and ground are reversed the motor will also reverse in direction.
- The rearview mirror control circuits are normally open at the rearview mirror switch.

CIRCUIT/SYSTEM VERIFICATION
Ignition ON, observe the outside rearview mirror while operating the outside rearview mirror switch. The mirror should move in the direction commanded.

CIRCUIT/SYSTEM TESTING

Outside Rearview Mirror Switch Circuit Testing
1. Ignition OFF, disconnect the harness connector at the outside rearview mirror switch.
2. Test for less than 1 ohm of resistance between the ground circuit and ground.
- If greater than 1 ohm, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the voltage supply circuit and ground.
- If the test lamp does not illuminate, repair the voltage supply circuit for a short to ground or an open/high resistance. If the voltage supply circuit fuse is open, also test the signal circuit for a short to ground.
4. If all circuits test normal, test or replace the outside rearview mirror switch.

Outside Rearview Mirror Motor Circuit Testing
1. Ignition OFF, disconnect the harness connector at the outside rearview mirror motor.
2. Test for infinite resistance between the mirror control circuits and ground.
- If less than infinite resistance, test the control circuits for a short to ground.
3. Install a test lamp between the control circuit for the particular motor and the common control circuit for the mirror motors. Operate the mirror motor by the mirror switch. The test lamp should illuminate with each command.
- If the test lamp does not illuminate, test the motor control circuits for an open/high resistance or a short to ground. If the circuits test normal, test or replace the rearview mirror switch.
- If the test lamp stays ON constantly, test the motor control circuit for a shout to voltage. If the circuits test normal, test or replace the rearview mirror switch.
4. If all circuits test normal, test or replace the outside rearview mirror motor.

COMPONENT TESTING

Outside Rearview Mirror Switch Testing
1. Ignition OFF, disconnect the harness connector at the outside rearview mirror switch.
2. Test for infinite resistance between all of the signal terminals and the voltage supply terminal and the ground circuit with the switch in the open position.
- If less than infinite resistance, replace the rearview mirror switch.

Outside Rearview Mirror Motor Specifications:

3. Test for less than 1 ohm of resistance between all of the control terminals and ground with the outside rearview mirror switch in the proper positions.
- If greater than 1 ohm, test the ground circuit for an open/high resistance. If the circuits test normal, replace the rearview mirror switch.

Outside Rearview Mirror Motor Testing
1. Ignition OFF, disconnect the harness connector at the outside rearview mirror motor.
2. Test for the specified resistance from the table above over the circuits in the outside rearview mirror motor.
- If the resistance is not within the specified range, replace the outside rearview mirror motor.

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
- Power Mirror Switch Replacement
- Mirror Face Replacement