Signal Lights...

I bought a 2006 international 9400i last week.(my first truck) It has a c13 with a 10speed Eaton. When I hooked it up to a trailer. I turned the the left signal light on and all of the lights on the trailer started flashing(including the running lights). I pulled my plug out of the trailer and put a test light to it, the left turn, right turn, and running lights were flash. I unplugged my calve from the back of the sleeper and put my test light to it..same thing. I replaced the signal light unit on the steering column, the flasher relay, and ALL of the fuses that had anything to do with light. Still the same thing. I checked all of the grounds. Nothing broke. Definitely need some help. I wish I had the funds to take it to a mechanic shop. But I do not.

 

So behind the plugin(inside the tool box/sleeper) there was three sets of wire connectors. I unplugged one of them and everything on the truck started working normal. But there is no power to the plugin points now..

 

Yes I pulled it off and cleaned it up. Nothing was loose or broke. Just a bit of dust. But nothing that would hurt.