caddy kid

I do a bit of camping in the camper shell of my long box standard cab 1994 F-150 XLT w/351. The shell has a battery powered light, but every time I need to use it, the batteries are dead. I would love to tap into a constant positive that is already in the back half of the truck so I can run an RV type light, but not sure if there is a constant positive back there already or what wire it would be. I do have the factory 7-pin trailer light connector, but the positive in that one is switched with the ignition key.

If I have to I can run a new wire, but would prefer to avoid that for a number of reasons if at all possible. Thanks!

Loganwildman

In a standard 7 way connector, there is a pin for constant 12v and many of the OEM harnesses include this wire but do not insert the fuse for it to make it live. I'd recommend checking to see if it's there, and then look at your manual to find the fuse location.
Here is a guide to identifying the pins and wires (although I would consult the oem wiring schematics for colors as they don' always follow the industry standard)
http://www.hopkinstowingsolutions.co...ring_codes.pdf

caddy kid

I will check that out when I get home. The OEM 7-pin connector cover does have a pin diagram on it, and the positive on that diagram is switched on and off with the ignition. Maybe I could figure out where that wire goes and make it a constant positive, but it may be easier to run new wire at that point. Either way, I will check it out. Thanks!

unit505

When I was camping out of my truck with the camper shell on it, I found many more needs than the RV light. Cell phone charger, 12v cooler, 12v fan, Etc. A roll of 8 gauge wire run from the battery to the camper using wire loom under the truck and stick on indoor plastic conduit inside the shell and in a few hours, I had 12v CIG outlets on both sides of the shell and my RV led lighting. I went overboard and installed a 25a master switch to kill the feed when not in use and had a small battery charger with a quick connector in the grill. I could hook up to camp ground power if I had it and watch TV, enjoy the fridge and even run my 12v electric blanket. Well worth the little money I had invested in it. Maybe $50. Just giving you some ideas for future planning before you run a single low amp accessories wire.

caddy kid

Chances are that is the route that I will need to go. Having more capacity than needed is always better than less! Never know what will end up going back there.

caddy kid

I wound up running a 10 gauge wire in a black wire loom from the positive lug on the side of the "power distribution box" (in front of the master cylinder) to the bed of the truck. Installed an inline fuse holder, and now don't have to worry about my light being dead when I need it.

The positive in the 7-pin trailer plug is a switched positive with the ignition. In reading the owners manual, they seem to call it a "trailer battery charge" circuit, so it makes sense that its only on when the truck is running.

unit505

Glad to hear you got it done.

Pat Simkins

I'm sure that the wiring in your trailer harness is at best 14 guage wire and NOT suitable for handling any current in excess of 20 amps. Running a new, fused line directly from your battery is your best bet. Be sure that your wiring and fuse is suitable for handling the current draw that you will be applying to the circuit or you'll be letting the smoke out in a hurry.

caddy kid

That was my thought as well. Currently I'm just running a single dome light bulb to the back, and that may well be all that I actually do. It would be nice to add a defroster grid, but haven't taken the time yet as that would require a bit of work to do right. In the meantime, its quite nice to have a light that I know will work when I need it, especially going into winter.