1. Check the fuses: Ensure the fuse responsible for the rear electric windows is intact and properly seated. If the fuse is blown, replace it with a fuse of the same amperage rating.
2. Test for power at the center console: Use a multimeter set to the voltage setting to check for power at the center console. Connect one probe to the center console connector's positive terminal and the other probe to a ground point (e.g., metal bracket under the dashboard). If you don't measure 12 volts, there's a problem with the wiring or switch assembly.
3. Inspect the wiring: Look for any visible damage or breaks in the wiring between the center console and the rear doors. If you find any damaged sections, repair or replace the affected wiring.
4. Check the continuity of the wires: Use a continuity tester to check the continuity of the wires connecting the center console to the rear door switches and motors. If you find any breaks in the circuit, repair or replace the affected wiring.
5. Test the switches: Disconnect the connector from the rear door switches and use a multimeter to test the continuity between the switch terminals. When you press the switch, you should measure continuity; otherwise, the switch is faulty and needs to be replaced.
6. Test the window motors: Disconnect the connector from the rear door motor and use a multimeter to test the continuity between the motor terminals. If you measure continuity, apply 12 volts directly to the motor terminals using a jumper wire. If the motor doesn't operate, it's faulty and needs to be replaced.
By following these steps, you can systematically diagnose the fault causing the rear electric windows to stop working in your 190 E Mercedes-Benz and take the necessary steps to repair or replace the problematic component.
