2003 Dodge Ram Trailer Lights

[dave524]

I own a 03 Ram, and it has a factory 4pin flat trailer plug under the rear bumper. this is great except that I dont have any signal for the right stop or turn comming from this plug. I have traced it up as far as i can go, and still have no signal. Any Dodge guru's out there that might be able to help? Thanks in advance as always, Dave

 

[freddyray21]

Re: 2003 Dodge Ram Trailer Lights

does your Ram have a separate light for the turn signals. If so I would bet it is the converter box that is bad.

 

[jtexas]

Re: 2003 Dodge Ram Trailer Lights

check the fuse diagram in the owner's manual - I was surprised to find (after tracing the wires way back into the vehicle of course) that my ford has separate circuits for left & right trailer brake/turn.

 

[SuperNova]

Re: 2003 Dodge Ram Trailer Lights

There are indeed seperate circuits for left and right. Check fuse #47 -15 amps in the underhood fuse panel. There is also a relay there for the right turn signals. The Front control module controls the ground side of the primary circuit, so you should have power all the time at pins #30 and #85, the fcm grounds at pin #86 and the trailer connector is connected at pin #87 all at the relay, which if you look at it real close there is a wiring diagram on it and all the pins are labeled. If you have the power where it should be, then do a resistance check from pin 87 to the trailer connector to make sure you don't have an open circuit, but if the fuse is blown check pin 87 to ground to make sure you DO have an open circuit to ground (NOT shorted to ground)-- should get infinite resistance ("OL" on the meter ). Then if all that checks out, take a test light and go from bat+ to pin 86 and turn the key on (engine off) and activate your right turn signal. The test light should blink as well, if all that works, it's either the relay, or your trailer.
--
Stan