Tow Wire Harness Not working, any suggestions...

[yeep740]

Installed the oem tow kit with plug and play wire harness, and cannot get the lights on the trailer to work?? Just wondering if anyone had this problem.

Thanks!

Brandon

[Tomaz]

Are you able to test for voltage at the socket? The problem may be in the connection or the trailer wiring. Good luck

[markesq]

I know this is old, but did you ever find the problem? I am going through the same isse.

[yeep740]

Ya... It was the hatch. No matter what I did to the slide out floor the noise never went away. So, I twisted out the bumper stops on the lift gate and that was enough to get rid of 90% of the noise.

Good luck

[markesq]

I was talking about the tow hitch plug. My trailer lights don't work either on the X5

[yeep740]

oh, helps if I read the post! It was my adapter plug. I got a different one and it worked. My boat had a 4 plug, and the OEM has a seven (round style) If that doesn't work check the fuses.

[TowX]

I frequently have to wiggle the trailer plug in the X5 recepticle. For some reason, the BMW piece isn't very precise and I've made it a habit to always check the lights before I take off on a ride. One thing I did was use some dielectric grease on all the plug contacts before plugging in, seems to help. I can run 8 hours without issue as long as I've wiggled the plug first to ensure contact.

Also, have you verified that you ahve power to the converter box that's mounted in the spare tire well area? Been a while since I did mine, but I know I had to run a power wire to the box, though that could have been the trigger for my electric brakes. But I know when I installed my factory parts, I had trailer lights even before I installed my electric brake controller.

Check the plug pins for power with the 4 way flashers on. If none of the pins in the recepticle have power you have a wiring problem.

[markesq]

I had the dealer install the hitch and wiring. Took it back to the dealer when it would not work on my 4 flat plug.

The dealer hooked the 4 flat adapter to the truck and used a volt meter to show me that there was a signal coming out for the lights and brakes from each hole in the 4 flat adapter.

Went back to the boat trailer, tried it today, and nothing. Plugged, unplugged, wiggled it around nothing.

Maybe I will go back with the grease and some WD-40.

[markesq]

Alright now at a complete loss. Bought a new adapter that had led lights to let you know if there was a connection. red lights all lit up, blinking when hazards were on, and nothing on the trailer.

Truly frustrated.

[JCL]

Is there a ground (earth) wire running to the lights, or does the trailer depend on the hitch being the ground? Worth checking.