Question:
I have a 2013 A3, that has been wired with a European market trailer setup. Works great with my European bike rack all lights work fine but I just recently picked up a trailer with a flat 4 pin connection. I tried the 7-pin to 4 pin adapter you guys have for a Land Rover, everything works except the brake lights. The more I read I realize other people had this problem too. Was hoping you guys could steer me in the right direction for a fix, and give me some part numbers. Sounds like maybe the best way to do it would be to wire the car for four pin, but I was wondering if theres any options to rewire the trailer? Long-term rewiring the car might be better but I just want to explore my options.
asked by: Stephen R
Expert Reply:
Since your Audi A3's European wiring setup works I recommend not messing with it and installing an independent 4-pole harness for your new trailer. Tekonsha 4-pole kit # 119147KIT is complete and includes the tester you'll use to identify the tail light wires you will splice into and all the needed connectors as well.
This 4-pole setup will give you the lighting signals you need and provide isolation and protection for the car's internal wiring from any faults or shorts on the trailer. Plus it eliminates any risk of interference with your existing European style wiring. You can refer to the linked video to see the install process.
Upgraded Modulite Vehicle Wiring Harness Kit w/ 4-Pole Trailer Connector and Installation Kit
Trailer Connector Adapter for Land Rover - 7-Way, Round Pin, European Style to 4-Way Flat