First off, this is my first post here so its nice to meet everyone!

My car is a 2002 ML500. The car had a factory hitch installed at 5000 miles (car is currently at 96,000 miles) and there is something overdrawing the amps on the brake lights when the trailer is connected. This problem developed last year. I know its not a problem with the trailer as I have tested the trailer with two other cars and it works fine.

Basically the directional indicators work, the parking lights work, but the brake lights work only for a second then the fuse in the ML (#15, 10 amp for the brake lights ) blows. Ive tried replacing the Delphi control unit in the rear of the car, but the problem persists. Once, while raining, the trailers electric brakes also engaged intermittantly on my driveway while going very slowly (thank goodness) even though I have no brake controller in my car.

Any ideas what the problem could be? I suppose it could be the wiring from the Delphi control box to the actual 7 pin female attachment point, however I have inspected the connector and no corrosion could be found. I tested the continuity of the pins and there is continuity between some that should not be conducting (cant remember exactly which). I suppose the next step is to replace that female 7 pin adapter, but I'm hoping this may have happened to someone else before.

Thanks for any help!

Jon