Trailer Wiring Help
 

I just had Uhaul install a hitch on my q7, however they cannot figure out the wiring. I called my audi dealer and they are a little confused on what to do next. Can someone please tell me the parts and part numbers that I need to finish this project? Also, if anyone has any recommendations on where to buy these parts from. All pics and instructions on the wiring are welcomed.

Thanks!!!

first you should check if your car is prewired. Most are, except for some early 2007 models. If so there will be a red plug sitting in the right rear access panel, right above where the navigation DVD drive is. This is where you plug in the trailer control module. on the other end of the module you plug in the harness that goes to the hitch itself. this is why getting a factory hitch for about 800 is a better bet. its alot more expensive than the uhaul or curt hitches, but comes with everything you need. Do not let Uhaul tap into your tailamps like you can do on some older cars. Thats trouble waiting to happen.

2nd that! Do not let U-Haul try to splice wiring. You need a trailer control unit as seen in this pic by mksap11
You also need to have adaption via VCDS.
That said you may already have the control module which is well hidden rear right just under the access panel. Together with the correct wiring loom its just a clip down and plug in.
Attachment 79773

from what i understand, you wont have the control module unless you have the factory tow hitch.

The bit I fail to get is... do we need this part? Every time a person asks about electric trailer brakes this comes up as there is a connector behind the footwell that is wired back to here but it must be connetced to a variable voltage switch which is physically connected to the brake pedal.
I do not have the electric trailer brakes but do have the control module/unit. Not sure how you are going to connect without it.
mksap11 also posted this pic while he was doing his own curt install.
So can you just connect direct to the harness?
How will you overcome bulb fail screen?
Attachment 79772

Ok great. Uhaul was smart enough to leave everything alone. Does any one have pics of the connection from the module to the hitch or pics of the finish product using a uhaul or curt trailer? Also, does anyone have the part #'s for the module, Hitch cover plate(??), and 7 pin connector? Please let me know if I am missing any part.

part # 4E0 907 383 E as shown in pic.
Here is the thread where those pics were originally posted. Includes entire control, cover, loom and ball part# and seperate replacement cover part# though I have seen some pics of cut out made by owners in originals.
https://www.audiworld.com/forums/sho...=2692144#27101

Total nOOb here - I've installed an aftermarket Curt hitch which fits up quite nicely. How do I deal with the electrical? Will the old school wire splicing with control module powered direct to car battery approach work? If not, will the Ausi dealer sell the control module on its own? Thanks all in advance!

On this car you defnitley want to get the control module from Audi. Most likely your Q is already pre-wired and you will just need the module and the harness. Once its all said and done, the savings going with the aftermarket hitch are minimal. You could purchase the Audi one with module, and harness for about 800 and based on some previous posts, it fits better than the curt.

As I already have the Curt hitch installed, can I purchase the control module only?