Tekonsha Prodigy P3 Trailer Brake Controller Install On a 2003 Mercedes ML350

Question:

So I have a questions regarding the brake controller installation. I have a 2003 Mercedes ML350 which has a harness built in to add trailer wiring. This harness has the following. 12V+ which is fused at the fuse box with a 25A fuse. Two grounds, Running lights, Left turn, Right turn, Stop and Reverse. I have wired to that harness a Tekonsha, Powered, 3 to 2 wire taillight converter and it works fine with a 4 flat cable. I wanted to add a Tekonsha P3 brake controller to the vehicle as well and was wondering if I would be able to also run the Tekonsha P3 off of that same harness for my power, ground and brake signal without any issues, or do they have to be wired separately for some reason? Thanks in advance.

asked by: Omar

Mercedes Trailer Wiring
(click to enlarge)

Expert Reply:

Your 2003 Mercedes ML350 is a vehicle we have never been able to put a brake controller on in our shop. It appears you are going to need the Wiring Kit # 5506 to install the Tekonsha Prodigy P3 # 90195 as I do not see any wiring for a brake controller on your harness. The Wiring Kit # 5506 contains the wiring and circuit breakers required.

If you are concerned about the additional wiring you might consider something like the Autowbrake # 3430001 which attaches to the trailer. As you already have the power for the charge line it would not require any additional wiring on your Mercedes.

expert reply by: Bud M