Trailer Wiring Harness Not Working On a 2013 Volkswagen Tiguan

Question:

I purchase this kit for my 2013 Tiguan and installed it using the BM-4 3-wire instruction, but on completion and testing, I get no lights on my trailer I previously had a 2011 Tiguan and installed this kit successfully, but using a different BM scheme that did not call for grounding the red and brown leads. Can you verify that the 2013 Tiguan should be set up using the BM-4 method. I want to verify this before I go back and try to troubleshoot. I believe something that I received tied the 2013 Tiguan to the BM-4.

asked by: Minott O

Expert Reply:

There is actually a plug-in style wiring harness available for your 2013 Volkswagen Tiguan, # 118675. Using this harness will prevent you from having to cut and splice wires. It is possible that you will need to follow a different installation method for the # 119250KIT harness but if you still have problems you can troubleshoot the harness.

To troubleshoot your # 119250KIT harness, if there is power at the 4-Way and all the signals are correct AND the trailer has LED lights then you will need to use an adapter. But first you would need to install # 37185, plug in your 4-Way, and ground the white wire to the vehicle frame. The other wires are not needed. Then you can use adapter # C35FR which is designed for use on certain German vehicles towing trailers with LED lights.

The other thing you can do is install load resistors, # DI34ZR, on each circuit on the trailer. This will provide more amperage draw on the system so the trailer lights will work.