I just bought this 06 Dodge 2500 crew 4X4 Cummins 6 speed 45,000 miles with trailer tow package. Here's the low down. No power at terminal for left turn in trailer plug. No power for left turn in the four flat plug either. Right side pin in the plug and the one on the four flat for right turn signal works fine. All of the trucks lights... both front and rear, stop, turn, and brake work fine. I just don't have any power in the trailer plug for LH turn. The OBD2 plug has nasty looking green corrosion on it. I can't find the plug under the dash for my new trailer brake controller either. When fuse 14 and or 16 is pulled from the fuse block, truck signals still work and the right turn for the trailer will still work. All appears to be OEM, and not all butchered up. I have no idea what to do from here, I have no schematic. Please, any ideas?

 

not sure what to tell you for the LH turn not working except to trace the harness under the truck and make sure its not pinched or rubbed through. these trucks when new come with a flat, 4 wire harness to wire up your brake control. if you look under the dash on the drivers side behind the parking brake by the floor you should see a plug that has 4 prongs and is maybe 2 inches long and flat. this is the where the harness goes that comes new with the truck. if you don't have the harness see where you can get one. it makes things quick and straight forward. check your owners manual too, i can't remember if they explain anything in there or not.

 

harness can be bought at a u haul place, or napa
i had similar problem, found a broken wire up near the fuel tank, had no power before the tank, working my way to the front of the truck, just after the tank, had power, so broken wire up behind the tank, i just spliced one in, and ran it to the harness after the tank.use a test light, works good, can pierce the wires and check every few inches at a time.

 

I have the pigtail coming for a Dodge for the new controller. Thanks for telling where the truck end is. As for the rear harness for the tailights, well, all I see is loom and tape. I really don't know where to start. I'm supposed to haul a 5 ton horizonal milling machine Saturday. I have till then to figure this thing out. I worked on it till dark tonight, then ran the battery dead on my LED flashlight, then came to the computer to DTR to REALLY fix it. I wish I knew something about the harness and how it connects to the main harness up front. The main branch coming out of the fuse block is the size of my little Brothers arm.

 

That's funny pullin hard, that's where I can't see the harness anymore, and probably where mine is bad too. I'll check real close tomorrow after work and see.

 

yup, i couldn't even get my hand back there between the frame and the tank, thats why i just spliced in where a had power, and routed a new wire to the other side of the tank, where i spliced back in, that way i didn't have separte wires running along the frame, and forget why they are there one day. when i pull my box off, i will fix better and feed it through the wire loom.i canged out my front control unit that does the lights, and it didn't fix the problem, which cost me 200 bucks for no reason. i now have a spare i guess. that is located under the battery on drivers side. easy the see if you pull out the drivers head light. i found a broken wire there too one time, but that was a head light wire. i have no idea if that does trailer lights or not.

 

check the fuse box under the hood, had a problem with my lights and I had three blown fuses. The left and right trailer lights and the trailer brake.

 

Fuses were all good. No light power coming out of the fuse box. I unplugged all the plugs looking for bad connections and took the fuse box out. When I put it back in the check engine light is now on. My OBD2 scanner won't read the code. It says there is a "linking error" but remember, I said earlier that the plug under the dash has green corrosion in it so I don't know if that's part of the problem or not. I'm not even sure my OBD2 scan tool can read codes on something this new. Guess I'm going to the dealer... I hate to give in. My equipment RARELY goes to town for repair.

 

i had an issue with mine and it was electronic based. they told me that the electric jack on the trailer tripped a sensor and it needed to be reset. bs i dont know but it works now and they didnt put any parts on the warranty bill. i havent had any issues since and use the electric jack all the time.

 

Fuses for the trailer wireing are electronic and built into the TIPM (totaly intigraged power module) If the TIPM sees more that 15 amps on a trailer circuit it shuts down that line and the TIPM needs to be reset by the dealer. There is a TSB http://www.dodgeram.info/tsb/2006/08-021-06.htm and the dealer can reflash the truck.

 

Took the truck to my Jobber Buddy instead of the Five Star. No, he doesn't have the Starsky Handset, but he bought an adapter for the 06 Dodge for his handset off the Snap-On truck. He was able to reset the truck and said everything checked out fine. No wiring problems. Just like Wv7o said, it's internally protected. I just wonder what the 06 see's in the trailer harness and doesn't like that my 94 Dodge didn't care about??? My Jobber said it could be a short to ground, or a bad board in one of my trailers LED lights. I need to check it out further. Regardless, if any of you guy's run into light harness problems, don't just start hacking up the harness looking for the problem. The problem could be on the logic side of the truck and not hardware related at all. My Jobber said ALL of the lights on this 06 are computer controlled. Thanks to all for suggestions and comments.