sh944s

I have a 2005 CTT that I have been using to tow my track car. All was well until my last trip where the brake and directional lights on the trailer stopped working half way home from Lime Rock. I first checked the trailer wiring and found that the mice had chewed the insulation in a few spots. The trailer is a few years old so I rewired the lights and brake circuits. I made sure the grounds were clean and actually added a couple of new ground points for good measure. I verified the wiring by ringing the it out with a 12v battery. All lights worked as expected.

I plugged into the Cayenne and still get the message and no brake or directional lights. Ok, I read the forums and find that the tow module can cause problems. I find a used one on Ebay, (out of the same vehicle, Rev and date code in the same model year) buy it, hook it up, still get the message. Switch back to the original module, still get the message and light issues. I check the wiring harness from the module to the Pollak connector, everything looks good. I have not rung out the harness but no visible damage. I decided to change the Pollak connector since it is cheap and can't hurt to change it. Still no brake or directional when I hook up to the trailer.

I check the voltage output at the Pollak connector with the brake pedal depressed and I get a voltage reading but it fluctuates between 14V and ~5v. Is this the result of no load on the pin? Is the Tow module limiting this due to lack of load?

I have read as much as I can find searching the forum. I can't seem to find the issue. I haven't gone to the dealer yet to have them check the module. Is it a programming issue with the module? Seems unlikely since both modules are not working in the same manner yet the original worked previously.

I am at my wits end...this shouldn't be this difficult. Any advice is appreciated.

stronbl

After reading your post, my very first thought was the trailer module needs to be reset / reprogramed by the dealer. It's a guess on my part, so take it with a gain of salt.

sh944s

Thanks, that is certainly one of my questions. But I have been searching some more and found a couple of post relating to electrical load. When I rewired the trailer, I fixed a some of the running lights that fell victim to the mice and were not working. Is there a number of lights on the trailer that will generate the proper load on the module so that is will function properly?

Right now the load is:
Running lights =8 lights
Brake lights/directional = 2
Break away battery charger

BTW, the lighting is incandescent, not LED.

BIG smoke

I hate trailer lights. It is always cold, dark, wet or snowing when they go down.
flat four pin? Or that big RV plug, 7 pin.
I seem to always need to scrub and clean that plug. Electrical contact cleaner, sometime a wire brush in there. Make sure there is no power to the plug before cleaning.
And die electric grease.

Have you tested your pins at the back of the truck?

sh944s

I rewired the entire trailer, new 7 pin plug and all. I also replaced the Pollak connector on the CTT. Everything reassembled with dielectric grease.

I do have voltage at the vehicle end. That is leading me to believe the load being sensed by the controller is either too high or low and therefore a warning is being displayed and the circuit disabled to prevent damage I guess.

SVOC

Was this issue ever resolved?