RedFalcon

I did a search but didn't find anything definitive. From the factory is there any kind of constant power back at the rear end of our trucks? I'm going to be installing my bed lights and was just hopeful that I was not going to have to run wire from the battery all the way to the back.

Truckin

iTrader: (4)

Tow package harness should have it..need to make sure relay is plugged in (mine was in glove box)

xcntrk

I think you're going to have to run something back. There's switched 12v power at the 7-pin trailer plug, but obviously that's not constant.

Feathermerchant

I have run a 12ga wire thru a fuse and to the back. Good, cheap mod.

Southern Dreamz

I have my bed lights on a switch that's wires into the 7 way trailer harness. Good because all the wiring is short, annoying to always have to have the key on to use the lights. I will be running a wire up to the battery one day for mine.

Truckin

iTrader: (4)

Plug in relay#5. It supplies 12 vt constantly to charge trailer batteries. .
That's what Ford mechanic told me when I asked what the relay was for..ccomes in the glove box with the tow package

Old Smoky

I ran a separate circuit, switched in the cab. Ran one under the hood and one to the rear.

xcntrk

I believe you're talking about the relay and fuse kit (AL3T-15A416-AA) found in the glove box of F150's with the tow package? The relay plugs into position 9 of the underhood fuse box located on top of the radiator, and the fuse plugs into position 21. This kit turns on the auxiliary 12v charging circuit on the 7-pin trailer plug (pin 4). The circuit has an overall capacity of 30A and is switched 12v power as previously stated, not constant power.

RaptoRx7

Another option would be to jumper slot 9...
Here is a good write up...

https://www.f150forum.com/f38/led-bedlights-143928/

Truckin

iTrader: (4)

Sorry dude..just going by what the service guy told me when I asked the question.