Taillight Converter on 2012 Chevy Captiva Illuminates Trailer Lights With Vehicle Off

Question:

I had purchased a trailer wiring harness for a chevy captiva back in March. Now when I plug my lights in then driver side trailer light stays on even when the car is shut off. What would be causing that one light to stay on? Doing a wire test there is power coming from the yellow wire when the car is off every other wire is off.

asked by: Alan E

Expert Reply:

It sounds as if the converter box has suffered an internal short which is allowing power from the battery feed to illuminate the left turn/brake light circuit for the trailer. This is caused by a short circuit in the trailer wiring.

You'll need to replace the wiring harness/converter. Before doing so however, you'll need to locate and repair the short in the trailer wiring, otherwise you'll keep blowing converters up. Start with the trailer connector, ensuring that it's not damaged or corroded. Trace each circuit back to its lamps, looking for pinched wires or wires with worn or cracked insulation that would allow the copper conductor to short out on the trailer frame. Make sure all wiring connections are tight and protected from the elements with shrink tubing or electrical tape.

expert reply by: Mike L