7 Way Trailer Plug Wiring Diagram Freightliner. Not sure which wires attach to what on your trailer connectors? Determine which color wire supplies constant power to the ignition switch.
I also made sure the contacts were clean in the male plug on the truck. Look at the wiring diagram for your truck's ignition switch. Wiring Diagram Sections The Freightliner wiring diagrams are divided by system function.
I double checked the wiring in my truck vs. the wiring diagram and it was the same.
Having the various pinout diagrams available is vital to troubleshooting and/or repairing truck.
The only way the dash lights go out is by removing the instrument fuse. The trailer side is the reverse of what you see below, but if you remember DRIVER SIDE/CURB SIDE it can be followed easily. Freightliner Electrical Wiring Diagrams and Schematic Diagrams.