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[khokhonutt]

Hi All,

I thought I'd post here to see if I'm missing something simple before I start digging further into my truck wiring.

I've got a 2001 F250 PSD with the factor towing package. I've been using the 7 pin plug for a while to tow my trailer, but with that trailer I primarily use the lights and trailer brakes.

Yesterday I was towing a box trailer for my kids' marching band. That trailer makes use of the 12V constant pin to run lights on the inside of the trailer. When we went to load the trailer last night, we realized those lights did not work.

I've checked the pin that should be the 12V power with a test light and it appears to be dead. Testing the wire (heavy orange wire) upstream, it appears to be dead as far as I can reach at the back of the truck.

This morning I checked the fuses that appear to be related to the trailer battery charge circuit (what I assume is the 12V line). Both the 30A fuse under the hood and the 10A fuse in the cab are fine.

Looking at a wiring diagram in my Haynes manual, it looks like there's a relay for the battery charge circuit. If that's the case, what activates that relay? Am I incorrect in assuming that line should be hot at all times?

Any info anyone can provice would be appreciated. Worst case, I'm going to run a direct line with a switch, but I figured I'd check here and see if anyone has any tips before I start crawling under and tracing wires.

Thanks,
Jeff