I'm having trouble with the plug for the trailer lights on my truck, I have running lights but no brake or signals, I have checked all the fuses under the hood and they're all good. There is no power from either the 7 way or 4 way for anything other than the running lights and I'm not sure what else I can check, any ideas? The wiring all looks good going to the bumper and I checked for power on the back side of the plug and there isn't anything going to it.

 

Maybe this is a dumb question, but did you check while stepping on the brake, or operating the turn signals?

 

I actually put the 4 way flasher on and couldn't get anything out of the plug, tried it with each signal as well. Same result with the trailer wire plugged in or not so I'm stumped as to what else to check.

 

Sounds like a fuse, but you checked that. Do you have a fuse diagram listing the fuses and relays? Vehicles with the center high-mount brake light usually have some funky circuitry for that.
Do you also have a fuse panel behind the passenger seat kick panel?
If it worked at one time, then has to be a failure and not missing wiring.

 

Don't look for fuses, there aren't any for the individual circuits. All this is controlled by the BCM, if the BCM senses something wrong with the circuit it turns it off.

 

Thanks for all the replies, I'll just take it in to the dealer on Friday and let them figure it out.

 

Good Luck. Let us know what they find.