2024 f150 XLT. I hooked up my boat trailer and the lights were very dim and I noticed the plug was smoking so immediately unplugged the trailer harness from the truck. I found I had a shorted market light on the trailer that had gotten pinched. I corrected that and replugged things in and have zero lights now. I’m thinking I melted the 7pin to flat 5 adapter. But I tested the 7pin on the truck with a multimeter and here’s my concern…I’m getting 14 volts to every pin except the trailer brakes and the reverse lights even with the headlights turned off. Shouldn’t I be reading no voltage to the brake, turn, running lights until they are activated? Can anyone confirm their f150 has hot pins with the truck running and lights in any position. I checked all fuses and all seem fine. Thanks

 

Only one of the pins in the 7 pin should be hot all the time. Are you checking voltage properly on each pin? Easiest thing to do is plug a trailer light tester into the plug and see if everything is still working on the truck
They are cheap and make things simple

 

Which one is hot all of the time? I have a '20, but I don't recall any of them being hot until you activate that component. Even the "constant hot" (7 o'clock pin if I recall) that feeds the trailer does not become hot until the truck is in gear, doors are closed and some other BS that the lawyers insisted on. I fought that battle with mine and ended up having to install a battery in the trailer so I could have lights, etc. when the truck is not running. YouTube has several videos showing this idiotic design flaw. That constant hot wire is also like a 20 AWG wire whereas the rest are larger 16 AWG.

 

Im saying one of the pins is 12 volt without any lights or signals activated not saying it would be hot with the truck off. I probably should have been more clear

 

You probably smoked a fuse.

 

Sorry I realized I’m just an idiot, I was looking at the wiring diagram but didn’t realize at first that my locator pin is on the bottom of the plug not the top like the diagram so I was off 180 degree checking my ground. So I was grounding on the 12volt aux pin the whole time. After I realized that everything was all good. Thanks for the help everyone!