Jeff Sweeney
Active Member
I have a 2018 Ford Expedition Max XLT. I have a relay connected to a wire that runs to my trailer to charge the batteries. I have been unsuccessful at locating the trigger wire to indicate the car is running or turned on. That was the quick story. I was using the charge pin port on the seven-way plug, but it was too frustrating letting the Expedition decide when to allow charge the trailer batteries. In either case, does anyone know a trigger wire that would turn on when only the car is running? I current been trying to find one, but my current one turns on when someone opens the door. That will not work for very long, as I will have a dead battery.