X5 Trailer Hitch Wiring Harness (7-pin plug)

usieve00 · #1 05-17-2006, 11:55 PM

Just installed the OEM hitch and wiring harness. The kit came with a 7-pin to flat 4-pin adapter and I assume as this is the most common for a standard trailer (ground, left, right, running).

However, the trailer I intend to pull has a flat 5-pin connector. The 5th wire is intended to be connected to the towing vehicles (X5's) back-up lights. This is because the trailer has mechanically accuated brakes using a master cylinder in the trailer. All is well when towing the trailer in a forward direction (ie. you apply the brakes and the resulting force is transferred to the trailer and the trailer brakes are applied. The catch is.....if you try to back up the trailer the brakes will be applied (again, force is being appled but this time from the tow vehicle pushing on the trailer).

That's where the 5th wire tied into the back-up lights comes in. When you put the vehicle in reverse, current is supplied and the trailer brakes are de-activated while backing up.

My questions...#1 Is one of the seven wires in the harness tied to the back-up lights on the X5? If, so anyone aware where to get a 7-pin to flat 5-pin adapter?

Thanks.

I am sure I could get out my light tester...but it seems easier to ask.

Sponsored Links

usieve00 · #2 05-18-2006, 02:09 AM

Well, after I posted my original message I went out and took another look at the wiring, and guess what.....

Right on the cover is a diagram showing the the wiring from the 7-pin connector on the vehicle side. The center pin is the back-up lights.

I think its fair to say I am just a bit embarassed.

JCL · #3 05-18-2006, 04:16 PM

Don't be. I put the hitch and wiring harness on myself, I have used it many times, I have been on this forum since the first week it was up, and I didn't know the wiring diagram was on the cover. Thanks for the info.

X5Dawg · #4 05-18-2006, 07:39 PM

You just need to buy a 7-round to 5-flat adapter and you are set!!

mdriverrad · #5 06-12-2006, 10:53 AM

Hi There,

I just bought an OEM hitch, a lot more difficult than I had previously thought. Any chance you can help me through it? Any chance you can help me with some good instructions? I am new to the site, this is my first day.

Thanks,

Rich

mdriverrad · #6 06-12-2006, 10:54 AM

Hi There,

I just bought an OEM hitch, a lot more difficult than I had previously thought. Any chance you can help me through it? Any chance you can help me with some good instructions? I am new to the site, this is my first day.

Thanks,

Rich

JCL · #7 06-12-2006, 03:32 PM

There is at least one very good how-to article on this site. Go to Home, then browse the articles. Lots of info there.

Sponsored Links