Trailer light Issues

[HTOWN///M]

Hey guys, im having an issue with my 2004 e53 4.4. Ive own the X5 for just over 2 months. It came with a pre-installed trailer hitch and trailer light socket. Never questioned it since it all looked factory etc. Well i just bought a new car hauler today and I picked it up with an ford excursion. lights all worked, turn signal etc. I get home and hook it up to the X5 and nothing. No lights nothing. So i figure maybe blown fuse or something. Check everything and its all good. So next option was to check to make sure I had power at the trailer socket on the X5. I have power but its fluctuates a lot. from 0 back up and so forth. I checked the trailer socket on the ford excursion and the voltage stay constant. so i assume that is my issue. Both the ford and the X5 are 4 pin and the trailer is a 7 pin but obviously that doesn't matter on the ford.

I did check the power coming into the control box that is by the battery and i'm getting constant power to it but after that box it appears the power fluctuates. So i'm at a lose. I cant figure it out . is there something i'm missing?

The e53 isnt new enough to need coding,is it?

Any insight will help

[wpoll]

Cant be sure but the voltage fluctuations may be the trailer control module checking for trailer lamps - it checks and reports lamp status to the CC module (LCM?).

Try connecting a 10w test lamp to the correct pins on the connector (with clippy leads) and see what you get.

The X5 trailer connector usually has more than four pins (more like 13 pins) - do you have an adapter?

[upallnight]

The factory X trailer wiring does not come with a 4 pin connector. If you have a 4 pin connector without it being an adapter that that goes into a round connector, you don't have a factory wiring, control module and maybe even the factory hitch.

Post pictures of what you have and we can tell you if it's a factory setup.

[HTOWN///M]

Ok some pictures to help..

this is what the trailer socket looks like on the x5


this is what the trailer hook up on the trailer looks like.


this is what came with the X5 that was plugged into the trailer socket when i bought the car.

[Riggodeaux]

The one pic of the hitch-mounted connector does not look like the OEM westfalia connection. That said, you may be too focused on the connector and not looking systemically to establish whether you have an OEM setup. Lift the floor under the trunk area and take a picture of the electronics behind the spare tire, and lay down under the back of the vehicle and take a picture of the hitch - not a close up, get at least the middle third of the vehicle at the hitch. Post the pix. If you don't have an OEM hitch, you do not want to try and pull a car hauler with this vehicle. That's a serious, perhaps fatal, accident waiting to happen.

[Riggodeaux]

Sorry, missed your point about the 'control box by the battery'. Why do you believe you have the OEM hitch? Take a look at the .pdf of the installation instructions early in the long DIY trailer hitch installation thread. Compare your hitch, and the 'control box,' to that in the instruction sheet. That will give a start to troubleshooting your setup.

[HTOWN///M]

The control box is siemens and has BMW on it.

[HTOWN///M]

I've followed the install instructions and have followed all the wires from the control box and have metered them and Im getting power but its fluctuating but after reading more it appears that is what BMW does to check the lighting for continuity. so i am at a loss. all i can figure is bmw wiring to the pin connectors is different but still unclear.

[Tomdownunder]

Are the trailer lights led? If so that can cause flickering of the lights as they are being monitored for continuity.

[HTOWN///M]

Sorry for the delay in responding. But I got the problem figured out. I had to re-pin the adapter. It was a simple 5 min job once I figure out what was what coming out of the x5. Metered them all and re-pin and boom! Trailer lights work.

And the 4.4 pulled the trailer and M3 with ease. Had no issues and x5 was a beast!