Connecting Trailer Light Relay / Any suggestions

[FortyPlus]

No one likes to admit a silly error, so sometimes the anonymity of the Internet is great

I fitted a Westfalia hitch to my (new to me ex-demo Q7 e-tron), selecting the simple detachable swanneck with relay-box driven lighting as my towing requirement is minimal (lightweight trailer or bike-rack).

I did this before on my previous car which had LED based lights, so did not expect any surprises.

So I followed the loom from the bumper lights and following a little probing, located the correct wires where the bumper loom entered the Comfort Convenience Control Module (Pictured)

Just as I was about to join the relay wires I had a thought: why do I never recall seeing these bumper lights on. Closing of the tailgate confirmed that bumper lights up only when the tailgate is open.. thus are unsuited to relay points for trailer lights. My only excuse is I am new to the Q7

Second photo shows the reverse of the Control Module, where various plugs carry cabling to tailgate & other modules.

Assume one of these must have lighting for Tailgate, but I was running out of time yesterday, so just put the sub back in, and reassembled things.

In this Audi video showing US hitch installation, at 1:35 it shows trailer module connections. Strangely, I don't recall seeing these connectors in my Q7 ( e-tron)



Any suggestions gratefully welcome.
As the photo shows, fuse-box is relocated in e-tron (certainly different to US Q7)
Pic 1 is general arrangement (with Bose Sub removed)
Pic 2 is underside of Comfort Control Module

Many Thanks
Hugh
Rear Electrics.jpg

Comfort Module.jpg

[anemeth]

OK, I thought that you have J345 trailer controller if you have trailer hitch fitted already.

If I am reading the wiring diagram correctly both tail lightes go to the CCCM. If you look at your picture they are the bottom left and bottom right 17 pin connectors. One is black, the other is brown. The tail light wires are mixed between the two connectors, thus one connector does not just cover one kind of light. The wiring diagram refers to "tail light" and "tail light 2", no clue which is upper or lower.