Tail Lights only

[kccobra03]

The other day my tail lights on my '01 F250 went out. Did all the obvious stuff like check fuses but none were blown. All other lights in the truck work fine except tail lights. I have been going over the wiring sch. from a Ford DVD but not sure where power comes from. Now this may have something to do with it, honestly haven't tried. I have snow plow, Fisher brand that uses a isolation box in the engine compartment. Im not sure if it has some effect. Haven't tried yet, cold out.

[silverF250]

Do you have turn signals?

[SuperCrutyPS]

Checked the bulbs?

[kccobra03]

Originally Posted by SuperCrutyPS

Checked the bulbs?

I ohmed driver side bulb and it looks fine.

[kccobra03]

I was wondering if power came from light switch? My front park lights r working fine. I found a relay #5, that I think goes to tail lights in the Ford DVD. And I believe the relay is inside the truck, dash

[kccobra03]

Has anyone had to replace the socket the bulb goes into? I just bought new bulbs and installed, traced the power wire down to a brown wire and it has 11.48 volts to ground so I thought it was the ground, which is the orange or green depending on which side your on. I have 11.48 VDC between ground and brown, +12V wire. What the Fudge? Has power, ground and still no light. I can only think the socket is burned up. Pulled the harness completely out at the back and looks great.

[SuperCrutyPS]

Originally Posted by kccobra03

I can only think the socket is burned up.

On both sides though?

[kccobra03]

I thought in an earlier post I had the correct wires but now have discovered not so. The tail light wires are Brown(+) and Black(-). I measured 8vdc at the harness. Im sure the ground is fine since the back up, stop, turn lights work fine. Im just still not sure exactly where the tail light are powered from. If I read the Ford DVD correctly it is straight from the switch. I want to make a stop at the ford dealer to ask them if I'm correct. For a temporary fix I have pulled power off the trailer connection and spliced into the tail light harness. Strang deal man. This truck had a 4x4 harness go bad 2 years ago. I bought the truck new so it isn't a flood vehicle or anything. The harness was bad at the power dist. box under the hood.

[silverF250]

Is the switch itself bad we had one got out on a Chevy and give the same results