Recommended Wiring Harness for 2005 Mercedes-Benz ML350 Special Edition with Factory Trailer Hitch

Updated 08/24/2016 | Published 08/23/2016

Question:

I have a 2005 Mercedes ML350 special edition sub with a trailer hitch but they didn't install the wiring harness with it. I'm confused looking at your site as to which one I'm supposed to get? All I know is that it is supposed to have 2 wires for each side because it has a turn signal that is separate from the brake light and my trailer is the 4 prong hookup.

asked by: Joe

Expert Reply:

Don't worry, I can help outfit your 2005 Mercedes-Benz ML350.

The wiring harness that I recommend for your 2-wire system is the # 119250KIT. I have linked the instructions for you to see how the 2-wire system your ML350 has will install. You mentioned the two wires as turn and brake light being separate but you did not mention the tail light wire, you could in fact have a 3-wire system which the # 119250KIT will also fit, best thing to do is to use the included tester for all the functions per each wire of your multiplex wiring. You will need to find out if the tail light has its own dedicated wire, which means you would not see the other turn or brake functions on when holding the tester to it, if it does then you have a 3-wire system not 2-wire. I spoke to my installer, and he highly recommended the # 119250KIT for your vehicle's wiring, because it has some of the best components for your multiplex wiring system.

In my research of your vehicle, it may be possible that they did run the wiring for the hitch, the plug for this will be behind the fascia cutout surrounding the hitch, there should be tabs to remove this panel and expose the wiring harness.

I have linked the above-mentioned product to this page for your viewing and purchasing convenience.

expert reply by: Jackie C