tneer1272, Lets eliminate some items. Since your running lights work turn them on, plug them in by turning the flat plug 90 degrees. Plug in the brown on the truck (pin) to the yellow (left) pin on the trailer harness, then the brown to green (right). Sounds like the back up switch worked tied to your reverse light circuit or you would not have been able to back up. The solenoid engages and blocks the fluid pressure from the cylinder when you shift into reverse. BCB