03 T600 cab power wire is energizeing the frame.

2003 Kenworth T600

Truck has been acting up the key would not start it so we jumped the solenoid to get it going (we changed the starter and solenoid) which worked for a week then it started clicking and after a couple attempts then would grab and start. The radio fuse kept blowing the parking/marker lights and head light relays pop when you turn them on.

The frame will turn on a test light from the ground to the frame. This only happens if the +wire that supply's the cab power is hooked up to back of fuse box ( we checked wire when its not hook to cab no power to the frame) Pretty sure at this point we have a short in the cab, Im guessing its a short from battery power because its constant if it happened with the key on then it would be in that circuit. Anyone out there ever had this problem or anyone have a schematic of a 2003 T600?

 

It started on and off slowly then we changed starter to please the driver after that issue was still there I checked the starter we took out and it works.