Brake Controller Recommendation for a 2012 Mercedes GL450

Updated 10/10/2013 | Published 10/08/2013

Question:

i have a 2012 Mercedes-Benz GL 450 I bought it new with the Factory Trailer/Tow package-I am looking to hook up an electric brake controller -Any idea where the wires are under the dash of the GL

asked by: Peter J

Expert Reply:

In order to install a trailer brake controller on your 2012 Mercedes GL450 it will require hardwiring in the controller unless the Mercedes dealer has a wiring harness specific for a brake controller and your vehicle.

If they do then you will need to wire in the controller to the Mercedes harness by function. On a brake controller, the wire functions are as follows:

White is ground
Black is 12 volt power
Blue is output to the trailer brakes
Red is input from the brake switch

On some vehicles like yours if you have to hardwire in a controller it can be difficult to get the correct brake switch wire for the brake controller red wire.

What I recommend is to use the Prodigy RF, # TK94FR. It mounts to the trailer and there is a hand held unit that goes in the vehicle with you. You just have to have the 12 volt circuit live on the vehicle side trailer connector for this unit to work. One big benefit using this controller has is that you will not need to hardwire anything into the vehicle wiring. I have included a link to a video showing a typical installation for you.

expert reply by: Michael H