I just purchased a 2007 Touareg and am about to put a trailer hitch on to it. Mechanically I can do the instalation but electrically connecting the wiring appears to be very complicated. Note that I want to hook up a 4 wire system. (running, brake and turning lights) I DO NOT NEED Electric Brakes or Aux Wiring.
I have the following questions:
1. The Owner's manual speciffically states not to connect lighting that has L E D's. Both my trailers have LED's. How do I connect for LED's ?
2. When I remove the bumper will I find a socket already installed ?
3. What do I have to do to the "Towing Recognition Control Module" ?
I have the 3 Widing Diagrams. (Number 25/2 25/3 25/4)
Not sure I'm much help. What I can tell you is that towing control modules need a certain amount of current flow out to the bulbs so the module knows a) that you are hooked to a trailer b) that your trailer lights are working c) if you have a bad bulb.
LED lights pull a fraction of the current that is pulled by normal taillights and such. Because of this, the module doesn't know what's going on. It can't sense the small currents.
However, you can go to any good towing and hitch shop (or even autozone) and buy load resistors. These are wired in parallel with your lights and allow sufficient current to be pulled that the module can "see" that you are connected and things are working.
I'm no expert on towing...just a guy who knows a bit about converting module-based electronics to LED from standard. Please don't rely on my advice to just run out and purchase some resistors and slap them on. Go to a knowledgeable towing place (most places that sell RV's are great options) and get some good advice from a guy who does that stuff for a living.
Because the Touareg has electronic stability control, the trailer module also communicates with the car so towing a trailer changes the stability control settings. It detects even non-braked trailers if the trailer lights are connected through the normal system. The normal VW hitch adds a large-diameter electrical connector (7 or 9 pins), but I picked up an adapter to 4 pins at Walmart or similar.
I no longer have my Touareg, and towing is the main reason I miss it.