Frozen001

No details... From what they told me it is behind the fuse panel, and it controlls everything. I am assuming what it does is convert from a 4 light to a two light seeing how my truck has a seperate signal and brake lights and on trailers there is a combined signal/break light.

Well I dropped it off to the dealer last night... Just got a call from them... They said it was the "flasher module"... I have not picked it up yet, but hopefully it works when I do.

OK so I hooked up the trailer last night to make sure everything was OK before the trip. Everything worked except the Right Trailer Brake light. The right signal works and when I use the 4-way flashers work, so it IS NOT THE PLUG, BULB, OR FUSE. ONLY the right BRAKE light does not work. I have no Idea where to even start looking. BTW the truck break lights work fine, and it is a GMC 2004 2500HD Regular Cab. So far I know this: Used a test light and I know the following: 1) The right pin on the trailer plug only lights up the test light with the signal 2) The fuse in the truck on the drivers side for the right turn/stop light will light the test light only with the turn signal, while the left will light with the turn signal and break light. ANY help would be great as I only have till Friday to get this working.