looking for wiring diagram

[Emory39]

Hi all,


I am looking for the AHM or trailer module wiring diagram, I've spent about an hour and a half looking for it, but I am not able to.



Any help is appreciated. I have the problem that the brake lights are always on, on the trailer. That said I am looking for the wiring to check if I could tap into that plug with an aftermarket wiring so that it ends up in the OE plug and not have to have wiring hanging from the rear hatch.

[Gregory891]

The wiring diagrams (particularly for North American sold cars) are the the rather helpful, thick Bentley manual (it's helped me for my Euro E53 as well).

For the tow bar / trailer hitch, what would be helpful to assist you - what wiring harness and system do you have? Westfalia (which is the OEM mfr for the E53)? You DO have the specific module (its in the largest compartment where your battery is located)?

Can we assume that your car's brake lights operate correctly (off and on) and that only the trailer is the problem? What results do you have when you use your running lights (1st position) or headlights (2nd position) or high beams?

[Emory39]

Hi, thanks for the reply. Its oe equipment. Oh the X the lights work fine. But when I connect the trailer the brake lights are always on. I read in other post the the culprit is the light module. But that cost about 650USD. I am seeking for the wiring diagram on the trailer module to see if I could piggyback an after market wiring to the oe 7 plug on the outside. So that I bypassed the trailer module but still get the trailer lights to work properly.

[Gregory891]

Open up the module and look for solder issues on the board or look for a good used one on Ebay.com.

[Emory39]

I did think on opening the LCM module to check why it's giving 12V to the brake lights all the time. I have an X5 that I interchange the trailer module just to check if it that was what was wrong with it, but it's doing the same. So it should be the LCM that is bad. I am finishing working on the X5 put in the suspension refresher right now then I will work on the X3 to check on that module. Will post findings.

[yes_its_neil]

Try this:

https://www.newtis.info/tisv2/a/en/e...ghting/nGKcdft

and this:

https://www.newtis.info/tisv2/a/en/e...ghting/XUd3ba1

[Emory39]

Originally Posted by yes_its_neil

Try this:

https://www.newtis.info/tisv2/a/en/e...ghting/nGKcdft

and this:

https://www.newtis.info/tisv2/a/en/e...ghting/XUd3ba1

Thanks!