How to splice one wire into the two-wire clearance light harness?
 

The original owner of my truck installed clearance lights that have one wire coming from each light rather than the two (black and brown) that were standard.

I have a factory wiring harness that will plug into the socket at the passenger side kick panel, but my knowledge of electronics is not good enough to know if I can splice the two.

So my question is, with the setup that I have, can I cut the harness plug off the factory wiring harness and splice that to the single wire that would supply the clearance lights with power?

** wire coming from underneath headliner. you can see that single wire exiting the cab to the clearance light above.
http://www.75lbhead.com/truck/f250_insideCab.jpg

** The comparison of the single wire versus the wiring harness's brown and black wires
http://www.75lbhead.com/truck/f250_wireComparison.jpg

** factory wiring harness plug and socket
http://www.75lbhead.com/truck/f250_c...ghtHarness.jpg

** type of clearance lights installed
http://www.75lbhead.com/truck/f250_clearanceLights.jpg

so lemme get this straight. you have 1 red wire coming from the lights up top, but a red and black from the truck to power them? then the lights are grounded to the body. splice the red to the red and ground the black wire coming from the truck to the body.

1st!!! GET RID OF THOSE HIDEOUS LIGHTS.

Those aftermarket lights ground to the roof w an attaching screw and a 12v wire to feed the lights.

The factory lights use a ground wire(black) and a power wire(BROWN) to feed the lights.

I would ditch the aftermarket lights and get a set of factory lights. i would also put rubber grommets or equivalent to keep the roof from chafing the wires

I'll try that. Thanks.

Those are aftermarket? look like cab lights from a 70ies model ford pickups?

Anyway no need to change anything unless you want to, no need for ground wire as they are metal, later model lights are all plastic so required ground feed.

I kinda like the lights so I think I'll keep them for now. Plus, I don't want to spend anymore cash. But, I can't with confidence tell you whether the lights are metal or not. There is a foam pad that sits between the roof and the chrome base. So maybe those are plastic.

Well, let me tell you what I did that didn't work (remember, I know hardly a thing about wiring or electricity. Beer makes me feel braver.) So I took the plus portion off the factory harness and spliced that (both brown and black) to the red. Probably a bad idead because when I plugged it into the factory harness at the kickpanel, the fuse blew and I had NO marker lights.

So of course I backed that genius solution out. Now it sounds like I need to splice the red wire from the lights to the brown on the harness plug, plug it in and take the hanging black wire from the plug and ground it to the chassis??

Just connect the red and brown wires together.You could ground the black one but there's no need to do anything with it because it's already connected to ground.

The foam pad keeps the water out of your cab so make sure the front and back mounting screws are tight.

You have two wires off the harness. One brown, one black. One provides power to the lights, the other is the ground. By twisting them together you shorted the fuse right to ground and it blew.

What I would do is attach the red wire of the roof lights to the brown wire ONLY, leaving the black wire not connected. Turn on the lights, and see if the roof lights illuminate. I bet they do.

This is because the black wire almost always is a ground, as is the roof metal the lights are screwed to - so those screws would provide the ground in place of the black wire.

Wrap the black wire end with electrical tape or install a wire nut so it doesn't short on anything.