2013 F150 - Wiring a little different

[kjohn73]

Our F150 light switch needs to be set on the second last position to power the trailer lights. Won't work on Auto. Okay.

When the truck is shut off, there is no power at all going to the trailer. I am guessing this is normal? On my old Sub, there was power to the trailer if it was plugged in. I had two batteries in the Sub and would just isolate one to be sure I had starting juice. The trailer has two 12v in parallel, so not too much to worry about for an overnighter.

Any ideas or observations on this, or is that the way it is, nothing more can be said?

Thanks in advance.

[mcfarmall]

Open the hood of the truck and open the power center box above the radiator. Check to see if there is 30A fuse in position 21 and a relay in position 9. If there isn't they should be in a plastic baggy in the glove box from the factory.

The relay indeed cuts power to the 7 pin plug when the engine is not running and the 30A fuse limits current draw by the trailer. It's Ford's way of isolating the truck battery when you leave the trailer plugged in to the vehicle and it's not running.

The trailer marker lights will work in Auto, but only when the vehicle turns the headlights on under low ambient light conditions or if you open a door or when you lock/unlock it with the clicker just like the truck parking lights normally do.

Being from Canada, your truck should have the DRL's activated from the factory. However, the DRL only turns on the headlights to a reduced level and the parking lights stay off.

[kjohn73]

OK. Thanks for the info! I notice that the marker lights come on when you unlock/lock the doors. It isn't a big deal the way things are now, but something I haven't had on a vehicle until this one.