Last year I installed my P3 controller to go with the new axle
and new electric brakes
. This year they have stopped working. When I connect the trailer to the TV, all the signals etc. work, but the controller says the trailer is not connected.
I'm not sure where to start looking for the problem. The TV has a 7 pin male connector, the cable has a 7 pin female on both ends and the the trailer has a 7 pin male to plug the cable into.
How would you troubleshoot this?
What sequence would you follow?