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OK, to put an end to this question: it appears that their is a Trailer Module (TRM) in the 2015-16 F250. This is what controls the charge circuit. As noted earlier, there is no actual relay in 102 nor can one be installed there.
On another post (which I can't find again) a member commented that Ford now controls the Trailer charge line with an intelligent battery monitor system. Basically, if it doesn't see a load (battery that needs charging) on the line it doesn't power the line. They also pointed out that this line isn't fed power until you crank the truck and put your foot on the brake (which since you have to put your foot on the break to crank anyway I wonder if he meant you have to put your foot on it a second time).
But the other thing I noticed is that the Orange wire (battery charge line) is TINY. It looks like a 18 gauge wire. What's up with that? I'm used to running 10 or 12 gauge wires from a battery relay to the trailer connector.
OK, to put an end to this question: it appears that their is a Trailer Module (TRM) in the 2015-16 F250. This is what controls the charge circuit. As noted earlier, there is no actual relay in 102 nor can one be installed there.
How did you get around this to get a constant 12v at the rear plugs?
As near as I can tell and for reasons I don't clearly understand, the charge lead does not become active until the truck is sure a trailer is connected. That assurance apparently comes from the brake controller finding the trailer when the brake pedal is pushed or, I am assuming the controller is activated manually. Once that happens, the charge lead comes online.
01-18-2016, 09:19 AM
