Ford Truck Enthusiasts Forums

Ford Truck Enthusiasts Forums (
-   1987 - 1996 F150 & Larger F-Series Trucks (
-   -   trailer battery charging wire? (

littlewhistlerlumber 11-18-2013 07:19 PM

trailer battery charging wire?
hello, im trying to get my slide in camper charging from truck system. i made a 7 wire cord to go between bumper and camper about 12' of 14 gage wire but there is a major voltage drop. so now i want to hard wire a in bed 7pin plug. im looking for the colors of the 12v trailer battery charging wire and also the color of the running lights wire that run on the frame on the drivers side. thanks
.. how are all your campers hooked up?

danr1 11-18-2013 07:26 PM


Google Image Result for

Nothing Special 11-18-2013 08:47 PM

Here's my setup

I got a project box from Radio Shack and a fuse block, a rocker switch, and an auxiliary relay from an auto parts store. I attached the fuse block to the bottom of the project box and attached the box under the hood hinge on the driver's side (it seemed like the best place). I also drilled drain holes in the bottom corners of the box. There's a cover for the box but I took it off for the picture. The picture shows more relays for other accessories. If you're only doing the one you could use an inline fuse and you wouldn't need the project box.

I ran 10 ga wire from the battery to the fuse block, from the fuse block (through a 30 amp fuse) to the relay and from the relay to the connector I mounted in the bed. Smaller wire goes from the fuse block to the switch to the relay. I also used 10 ga wire for the ground from the plug to the truck frame.

This setup lets me turn the feed on and off, so I don't drain my truck battery when the camper is parked. You do need to be careful with any setup not to use it when the camper battery is drained too far, it'll blow the fuse. If it gets drained too far you'll need to charge it another way first.

littlewhistlerlumber 11-19-2013 09:36 AM


My truck already has the wiring to the bumper 7pin. I was hopping to splice to the 12v power as well as the running lights off the lines that go back on the drivers side behind the cab leavening my 7 pin for a trailer. All I need is the color of the 12v trailer charging wire and the color of the running light wire thanks a bunch

littlewhistlerlumber 11-19-2013 09:38 AM

I spliced the 12 ga red thinking it was the charging wire but it seams to be 12 v with the key on and off looking for a key control

Nothing Special 11-19-2013 11:37 AM

I don't think there is a key-controlled 12V wire anywhere in the truck that is fused high enough to supply power to a trailer or camper. That's why I went with my own fused source and a switch/relay. I could have taken any low-amp accessory power feed to control my relay if I wanted it key controlled. I just chose to add a separate switch

All times are GMT -5. The time now is 08:50 AM.

© 2019 MH Sub I, LLC dba Internet Brands