Q: How can the functionality of electric rearview mirrors be tested on Chevrolet Colorado and GMC Canyon?
A: The electric rearview mirrors utilize two motors to adjust the glass, one for vertical movements and the other for horizontal adjustments. To test the functionality of the mirrors, ensure that the ignition is in the ACC position and the engine is turned off. Roll down the windows and operate the mirror control switch, testing all functions for both the left and right side mirrors. Pay attention to any sounds emitted by the electric motors within the mirrors. If the motors can be heard but the mirror glass does not move, it is likely that there is an issue with the drive mechanism inside the mirror. In such cases, the entire mirror unit must be replaced as it does not contain user-serviceable parts. If the mirrors do not operate at all and no sound is produced, it is advisable to check the Fuses. If the fuses are in proper working condition, the next step is to remove the mirror control switch and have its continuity checked by a dealer service department or a qualified shop. Additionally, it is important to inspect the ground connections. If the mirror still fails to function, remove it and examine the wires at the mirror for voltage. If there is no voltage in each switch position, it is necessary to inspect the circuit between the mirror and control switch for any opens or shorts. However, if voltage is present, remove the mirror and conduct a test off the vehicle using jumper wires. If the mirror fails this test, it should be replaced.