Tail Lights Out - 2000 4.0 4x4

[dirtysturdy]

I got stopped on the freeway last weekend for having no running tail lights. Looks as if both lights went out simultaneously. Break lights, turn signals, reverse, and hazards all work. Just no tail lights. It's possible that I dipped a connected 4 prong launching a boat a few weeks ago, but I imagine I would have noticed the issue before Mr. police did.

Bulbs are fine. Neither the Ford manual and the Haynes manual mention tail lights at all, however all the fuses look good. Any clue?

 

[RonD]

The Brown wire is for Parking lights front and back and license plate light bulbs

Do the front park lights work?
Do the license plate lights work?

There is a fuse in engine fuse box, 15amp, and a relay in the cab that power all the parking lights, so if it is just the rear lights then those are OK, and you should start tracing the Brown wire at the rear of the truck.
Ground should be OK if brake lights work
yes, check the trailer connector although if there was a problem there I would expect fuse to blow and all parking lights would be off

 

[dirtysturdy]

Thanks. Yeah the front parking and license plate lights both work. I'll start tracing the brown line.

 

[RonD]

Found this 1999 Ranger exterior light diagram

Looks like a problem between S401 and S407 would effect only tail lights not license plate lights.
If trailer light connection was not factory then installer could have splice into that wire and didn't seal it so it started to corrode and has failed at that point.

 

[dirtysturdy]

Thanks Ron. The brown was somehow sliced right under the connector.

 

[Doofy]

Ain't life grand! Good troubleshooting! This is why this is a wonderful forum. People are willing to share their knowledge to help others. Often, just a small nudge in the right direction is all it takes to strike a spark of confidence and good things happen.