For a while now, I have been fighting with mine to keep it in working order....Bought an entire new harness from Mullane Dodge....It was defective right from the factory...

Been trying to no avail to get my trailer brakes working...Ran an entirely new wire all the way back...Still no good, and now my running lights are out.

When I spiced into the harness near the connector, one wire in the harness broke right off, fixed that, but I bet one other broke now, and didn't actually snap completely.

What is it with the Dodge wiring? Every single damn truck I have had needs a new harness. This one the factory connector doesn't even work, no signal right at the plug!

What do you guys use to trouble shoot them without the trailer?

Test light generally.

I don't know what year truck you are talking about but I had the same issue on my 2004 and it was the FCM (Forward Control Module) that went bad. First my right turn signal for the trailer quit working then the trailer brake lights. The FCM is the little metal box attached to the TIPM (fuse box). There are major issues with the fuse box also, had to end up replacing mine.

Right now, everything on the truck tests out correctly with a test light, pin by pin. I might have got it, or the trailer has a bad ground or the e-brake box is toast. I cannot find anything wrong. Fuses are all good, and I have 12v at the 7-pin connector one by one.

If the e-box is toast, would I get 12v on the blue wire at the pin?

Again, what year of truck is it? When they went to the 3rd gen every single connection goes through the TIPM and FSM so it does not matter what circuit works and what doesn't as they are all separate.

In addition that front control module will only reset so many times then it needs to be replaced. The way to fix it is to run all your trailer lights and brakes off of relays so the fcm doesn't get over loaded.

Its a 2003...

I hooked it to the trailer today, and eveything now works on the trailer but the brakes. I tested every pin on the truck probably three or more times, and I am confident I got all the wires on the truck fixed.

I see a wire under the trailer near a wheel hanging, and i need better weather to get under there...One bet its for the brakes.

I replaced the trailer harness up to the junction box, just three years ago so I guess both truck and trailer have issues...Sucks towing all the time.

As mentioned before the trailer brake circuit can be easily diagnosed with a test light. Hook the ground lead on the light to a good ground on the truck. Touch it to the 12v trailer power terminal to ensure you have a good ground and the test light illuminates before checking the trailer brake circuit. Have someone activate the trailer brakes and your test light should illuminate and should intensify brightness as the gain is turned up on the controller. All the controller does is modulate the voltage to the magnets on the trailer brakes. Simple as that. If you have a wire hanging loose by one of your trailer wheels then it is highly likely a brake magnet wire for either power or ground to the magnet. Most of the trailers I see have those worthless scotch-lock wire connectors that either corrode or become unattached. Don't use them. Solder and heat shrink all your brake wire connections if you don't want to constantly chasing trailer brake issues.

I kept loosing brakes due to those crappy connectors so I soldered them and used heat shrink and haven't had a problem since.