Hello all! I am new to the forum and have searched and searched and not found an answer. I have recently bought a 2008 2500 with the 6.7L. The truck had an aftermarket trailer plug that did not work. It was all corroded and rusted out. I purchased an aftermarket replacement. I got out the DVOM and tested each wire while wiring it together to make sure they all went to the correct place. When I was done all of everything worked perfect except the left turn signal and brake light. All fuses are good. My main confusion is there is one wire for the right turn and brake but there are 2 for the left. One yellow wire is turn and one is brake and turn. I tried using just the brake and turn and still nothing anybody have any thoughts or ideas? Thanks in advance

 

maybe this will help, good luck.

http://www.etrailer.com/faq-wiring.aspx

 

So this doesn't help too much. I traced the 2 yellow wires back and they are the same wire. It looks like one was split into 2 for the 7 blade plug and the 4 pin plug. I have found a lot of info and people having this same issue on the 2003-2006 models. I have read that it is related back to the TIPM. Anybody have any thoughts on this or has anybody experienced this issue in the 08's Thanks.

 

I got a powered trailer light module and fed the inputs directly from trucks rear lights...problem solved for ever....

 

Jeep Man.

There is some unknowns here:

How many prongs on the aftermarket plugs?
How was the after market plug tied into the system?
Did it have part of the system tie into the 4 way under the bumper?
I'm assuming you have truck lights but not trailer lights? (this would indicate a TIPM problem and or bad wiring)

Like the above poster stated an aftermarket modulite is probably the cheapest solution as a new TIPM can run a $1.000 if it can not be reset.

Here is the link to that system:

http://accessories.etrailer.com/search?w=modulite