working on 04 2500 4x4 i have no right turn signal at trailer plug traced wires back to about fuel tank still dead wire .. all fuses are good . was going to check at plugs on the innner fender well .there is 2 plugs a big one and small one . withc one has the trailer wires ??? looks like the big one and it looks like a litght green wire . if still dead there anyone have any ideas ? all other lights work on truck and trailer plug

 

All fuses as in the separate fuses for the trailer lights? if the fuses is good you probably need one of these:

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

 

all fuses r good seems like wire is dead some were maybe rubed threw or rotted off some were

 

Eitehr that or the relay is smoked in the FCM.

 

^^^ What he said ^^^

You can do a search on how to replace them or just install a modulite.

 

oh fcm what is that were is it ? like to make sure that is what is rong still need to trace wire back more going ot try at the plug in the fenderwell

 

Front Control Module. It should be under the fuse box. The fuses are the safety feature but the circuits are powered from the FCM and controlled by the PCM portion of the ECU. The relays can go bad on the FCM board and will need to be removed and a new one soldered in.

Just be happy you don't have an 06+ with a TIPM. When they go completely out your replace the whole thing instead of a relay.