Towbar electrics help

[patrickhorton]

I've fitted a towbar to my A4 avant (56).

The electrics are giving me a headache. I have a dedicated Westfalia kit and I think I have crossed the CANbus connections. None of the "central electrics" work when the towbar box is connected - it's like the car is dead but the engine will run. Put the old wires back and everything fine.

Westfalia instructions are poor and the inference is that the orange green and orange brown wires of the towbar box should not connect to the ILM (near the fuse box) where the old wires of the same colour went - they should be reversed.

Any advice appreciated.

Patrick

PS. I have used an excellent guide which I downloaded from here (I think) - a 14Mb pdf.. I have struggled to find the original link to the file but will post thanks and other comments when I find it. Any pointers to the source?

[patrickhorton]

All working now. Reversing the wires again got the towbar box running.
Anyone doing this can rest assured that crossing these wires does no damage.

Regarding dedicated towbar electrics the Westfalia kit (Hella branded on electronic module) is for left hand drive cars, I'm pretty sure. The one I got from Towequip had too short a wire length to get to the fuse box. It can be fixed by cutting open the loom at the towbar box end to release another foot or so of wire.

The dedicated kit enables the towing features in the dash display. I get "trailer bulb failure" messages for each bulb and an extra indicator lamp in the dash flashes when turning with a trailer on. Also the rear fog does not come on when towing. With my 56plate A4 I don't think there are any fancy ESP or stability features enabled when towing. This is a feature of later cars I think.

Can't recommend the Westfalia detachable bar enough. It is really well made, totally invisible when removed and almost no bumber cuts. The electric socket also folds away behind the bumper when not in use.

Hope this is useful to someone.

Patrick

[trevor250]

Patrick,

I have an A4 Saloon SE 2.0T FSI S-Line 2007 model, first registered 31/07/2007 (56 plate). I am going to purchase the Westfalia detachable towbar, however I am confused about the electrics. I would like dedicated electrics and will probably find your advice useful, come the time to install. Can you advise who you got the electrics pack from, and did you have to get the Audi dealer to reprogram the ECU to enable the features you mention?

Many thanks,

Trevor

[patrickhorton]

Hi Trevor

I bought electrics pack 305210300113 and towbar 305302 from Towequipe via Ebay. I think it worked out much cheaper via their ebay shop. I believe these parts are the same as the OEM Audi kit. You have to use VCDS or VAGCOM to tell the ECU that the towbar electrics is fitted - this is easy to do if you can get hold of the kit. Without this nothing on the trailer board will work. When working you get a nice bulb fail indication in the instrument panel when a trailer bulb fails.

Good luck

Patrick