What is the Correct Trailer Wiring Harness for a 2010 Mercedes GLK350

Updated 04/11/2013 | Published 06/02/2011

Question:

When I googled the GLK wiring harness I was brought to the 119176KIT saying it was compatible. But when I use the hitch finder in your site, I am brought to the Curt PWM module. Will the 119176KIT work with the GLK? Its cheaper and already includes all the wiring needed.

asked by: Jack

Expert Reply:

The correct wiring harness for a 2010 Mercedes GLK350 is the Tekonsha Upgraded Heavy Duty ModuLite Harness, # 119250KIT. It contains everything you need to properly wire your GLK. Part # C59496 is configured differently and will not work with your vehicle.

I have included a link to the installation instructions and a video showing a typical installation for you to view.

expert reply by: Michael H

Stevem

3/20/2013

I was helping a friend install a hitch and Curt 56200 wiring harness on his 2010 Mercedes GLK 350. We are both engineers by profession not sure if this help or hurt.When checking voltage at the rear taillight assemblies, there was more than 1 wire on each side which changed voltage with the turn signals.Is there a definitive answer regarding which wires to tap into for this application? Obviously, we dont want to cause any problems with the vehicle, Im just hoping to find specific instructions for wiring this vehicle.Thank YOu,Steve M.

Patrick B.

4/11/2013

You have found the same frustration we have been dealing with. Mercedes, BMW, Audi and other European manufacturers have switched to more complex wiring systems that utilize PWM or Multi-Plex circuits. We do not have the definitive color code or voltage read-out for that vehicle. Since the power draw is coming from that dedicated power feed, there should be no risk to the factory wiring. Also, of the two wires on each side that changed voltage, did one of the two change voltage with the brake pedal. You want the wire that changes voltage with turn signal and turn signal alone for connecting the yellow and green wires for turn on either side of the vehicle.