1. Fuses: Start by checking the fuses in the fuse box (both under the hood and inside the cabin). Consult your owner's manual to locate the fuses responsible for the rear power windows. Replace any blown fuses.
2. Relays: Power window operation often involves relays. These are electromechanical switches that control the power flow to the motors. These can be more difficult to test and might require a multimeter. If you're not comfortable with electrical testing, a mechanic should handle this.
3. Window Switches: The switch panel itself could be faulty. Try testing the switches by using a multimeter to see if they're sending a signal when pressed. If you have a second-hand switch panel you can swap it to confirm if that is the faulty item. The rear window switches might be part of a larger master switch. A faulty master switch is possible.
4. Wiring: Check the wiring harness leading from the switches to the window motors. Look for any broken, frayed, or corroded wires. This often occurs where wires bend or flex frequently. This inspection might require partial disassembly.
5. Window Motor(s): The motor itself might be faulty. This requires removing the door panel to access the motor. You can test the motor directly with a battery and jumper cables (be extremely careful when doing this to avoid shorts), but this is best done by a mechanic unless you're familiar with car electrics.
6. Window Regulator: This is the mechanical part that raises and lowers the window. It may be jammed, broken, or stripped. This would prevent the motor from working even if it's functioning. Again, this requires door panel removal to inspect.
7. Body Control Module (BCM): In some cases, a faulty BCM can prevent power windows from operating. This is a more complex issue that usually requires professional diagnosis.
Troubleshooting Steps:
1. Start with the fuses. This is the easiest and cheapest fix.
2. Check the switches. Are they making a clicking sound when pressed?
3. Visually inspect the wiring. Look for any obvious damage.
4. If all else fails, consult a mechanic. Diagnosing and repairing more complex electrical problems or mechanical issues requires specialized tools and knowledge.
Don't attempt repairs beyond your skill level. Working with car electrical systems can be dangerous if not done correctly. If you're unsure about any step, seek professional assistance.
