Troubleshooting a Wiring Harness for a 2022 Volkswagen Tiguan That Lights Don't Turn Off

Question:

Hi there. I installed this on my 2022 Tiguan and it worked great for a little while but I have an issue now and am trying to figure it out. My trailer lights will stay on even while the car is off. My blinkers not brake lights on the trailer won’t work and the lights will also slowly dim and brighten. I have checked continuity throughout the trailer and it all checks good. Can you provide some insight on what to look for next? Thank you

asked by: Jon

Expert Reply:

Usually whenever things like this happen after they've previously worked, that's a tell tale sign that there is a damaged or corroded connector.

You might still be getting power to the circuit, but the connector is corroded or damaged and that's causing the lights to not function properly.

I'd recommend checking the connectors and looking for white or green corrosion on the pins or sockets of the connectors. If there is, you can try cleaning it and seeing if the problem continues, if it doesn't fix it then there's a good chance that the corrosion spread to the interior of the connector and would best to just replace the harness.

expert reply by: Bryce D