Most power folding mirror issues stem from the folding motor (fold actuator). You can quickly locate the fault by symptoms:

A crunching or grinding noise while the mirror folds usually indicates a faulty fold actuator, typically caused by worn or jammed internal gears. If the mirror folds very slowly and lacks torque, the motor itself is nearing end-of-life, most often due to worn carbon brushes. When the folding function stops working entirely, the fault may lie with the fold actuator, the control module, or wiring, which requires further inspection.

You can also use a multimeter for precise testing: Unplug the connector of the folding motor and set the multimeter to resistance mode. Measure across the two power pins of the motor.

• A stable resistance reading means the motor winding circuit is continuous.
• Infinite resistance points to an open winding, and the motor is defective.
• Near-zero resistance indicates a shorted winding; do not apply power.

⚠️ Important note: A valid resistance reading does not guarantee the motor is fully functional. Mechanical defects such as slipping gears or poor carbon brush contact can still exist even with normal resistance. If possible, supply the motor with its rated voltage separately to verify smooth operation, abnormal noise and rotating speed.

Summary: Grinding noise or slow folding prioritizes inspection of the folding motor / fold actuator. If there is no movement at all, test the motor with a multimeter first to tell apart motor failure from faulty control modules or wiring. This prevents incorrect part replacement and cuts unnecessary costs.