Just installed A 4 PIN TO 7 pin plug for the 7 pin on my AS. The 4 pin is the standard on Ford Trucks from 2006. The blue brake power cord was there and I spliced it onto the blue 7 pin connector. I also grounded the white wire to the truck.
I have power in the 4 pin as tested. I seem to have power in the 7 pin part as my volt meter reads 12v
across the connectors.
My umbilical will light up the trailer lights when a fuse is placed across the connectors while the trailer is on shore power.
BUT - I have no lights or brake connection when the umbilical is plugged into the truck end.
What the heck can this be? I opened up the trailer wire compartment and all is well. Cleaned the connections to be sure.
Cleaned all connection plates on the trailer umbilical with contact spray and a small screwdriver.
Help me troubleshoot this please!