Problems on the Highway: Tail and Dash Lights Out
 

Hey Guys,

My brother has a 2002 F350 and his dash and tail lights keep going out while hes on the highway in the dark.
He replaces the fuse and all is well until he gets underway again. Once he gets up to speed the dash lights will flicker a few times and then go out, blowing the fuse.
Hes replaced the fuse a few times with the same results. Its raining out too if that gives any clues.
Where is the best place to start to look?
I'm guessing there it is shorting out somewhere , but where...?

The windshield on the left, where the fusebox is located.

Thanks Mark, you think the short could be originating from the fusebox area?

Gotcha, why then would it only blow the fuse when he gets up to speed?

That's a good question. but the fusebox is a place to start.

Will do, I'll let you know what he finds.

Thanks for the quick replies!

I'd start at the wires near the back. Might have a bald spot and if they're loose they might be flopping around in the wind. If someone tapped into them for a trailer lighting connector that would be the first suspect.

Has there been any modifications to the wiring? First key to troubleshooting electrical is what was the last thing done before the problem showed up, or the last incident that happened, wreck, flood etc...

Thanks for the feed back guys. After speaking to him he said that there was a splice made in the back for his trailer wiring in the not so distant past.
He will start there and check the fuse box for indications of shorting or water damage.

All depends on the details. What's it doing, is your wiring modified or visibly damaged, etc.