2006 Mercedes R Series 4-Way to 7-Way Trailer Connection Recommendation

Question:

used tekonsha modulte trailer light power module lights work , directionals work, running lights work brake lights do not work. flat 4 wire on car flat 4 from 7 wire we do not need trailer brakes

asked by: Bob S

Helpful Expert Reply:

The Tekonsha ZCI Circuit Protected Vehicle Wiring Harness w/ 4-Pole Flat Trailer Connector and Installation Kit # 119250KIT is my recommendation for your 2006 Mercedes R-Series. This will give you a working 4-way flat. To get a 7-way connector, you would then just need to add the Hopkins Endurance Multi-Tow 4-Way Flat to 7-Way RV Trailer Adapter w/ 4-Way Vehicle End Plug # HM47180 and make sure the white wire with terminal is grounded to bare metal so your lights can work properly. Remaining 3 wires can be left unused and taped out of the way or you can connect the reverse function and 12V power using a circuit breaker like # 9510 and run wire # 10-1-1 to the positive battery terminal.

It sounds like you may already have a system that just needs the 4-way to have a better ground. Make sure it is metal to metal and free of debris and corrosion. Test with a circuit tester like # PTW2993 for function. Then replace or add the 7-way adapter mentioned above.

expert reply by: Jason S