bailer6334 wrote:
Bob,
I was on another forum and they were discussing the same problem you have. Sorry can not remember the forum, but the cause was a bad connection between the truck wiring and at least one of the pins in the 7 pin plug. Not enough voltage ( I think 12-15 volts is normal)was going through the pin to activate the brake controller properly. GM techs did not find the problem, a trailer hitch tech discovered it.
Hope this helps isolate the problem.
I have a 7 way plug tester and the brake light just flickers when I apply the trailer brakes, a trip to an rv place cost me 295 bucks and was told everything was rewired from the ITC back to the plug. Still did not work. A trip back with two techs working on it telling me the controller was not sending voltage back to the trailer pin. Got a 50% discount and paid 115 bucks. Took it to the dealership to have the ITC replaced. They called and said nothing was wrong and they hooked it to a TT and the brakes worked......BUT they did not tow it just listened to hear the magnets. I took it hooked it to my 5th wheel and with my wifes help I could just barely hear the magnets and there was very little resistance when doing a pull test. I am at a wits end as to what my problem is.....It is keeping me awake at night.