Brothers truck keeps blowing Instrument/Running light fuse

[6 Nebraska IDIs]

My brothers truck has been blowing the instrument panel and running light fuse for a few days. He replaces the fuse and it will only last until the first bump then its gone. I told him to check the headlight wiring for the switch thats a common place for OBS trucks to short out. He's looking for other ideas as well. He's not very good at wiring problems, and taking it to a mechanic for work is out of the question. So keep it simple stupid for him. lol

 

[OLDBULL8]

If he has a trailer receptacle on the rear, check there. Check the taillites for burned out bulb, sometimes the filament if broke loose will short out.

 

[KyleQ]

My 95' does the same damn thing!

I took my dash out and somewhat haphazardly installed it again, I'm thinking it could be as simple as not having everything plugged in - I don't think my ashtray is there, could be dangling and shorting.

Check the trailer wiring - it unplugs on the back of the truck, look at those connectors and see what is going on. Beyond that - I would check wires for resistance and see if anything is unusually high... Hate wiring....

 

[freebird01]

my f150 did this but like an idiot i put a bigger fuse in and it fried the wire into the headlight switch plug. now i got to pull the dash to wire in another plug

 

[hahn_rossman]

It's the headlight switch, if it isn't some mickeymouse trailer wiring that a previous owner hacked together. It's super frustrating.

 

[6 Nebraska IDIs]

Thats exactly what it was Hahn. The switch looked brand new but we replaced it in a blind effort to fix it, and it did. Crazy.

 

[TWeatherford]

For future people that might dredge this up on a search, mine did the exact same thing for about a year till I finally looked at the headlights. I'd had the bed off shortly before the fuses first started blowing so I was sure I had accidentally squished something back there. Once I pulled the driver side headlight, it was super obvious where the wiring was grounding. Some shrink wrap and I've not had to replace a fuse since!

 

[Jake_IN]

I'm just gonna add that in my case it turned out to be my license plate light harness. Where it connected to the frame harness it hung down and rubbed against the edge of the frame rail and grounded out there.

 

[Drew2010]

I'm just gonna add that in my case it turned out to be my license plate light harness. Where it connected to the frame harness it hung down and rubbed against the edge of the frame rail and grounded out there.

Just throwing out another Idea...

Also if you have an aftermarket stereo, there is an orange wire that was the dimmer for the factory radio; it is not used in aftermarket head units. I had the running light and dash light fuse blowing often, finally one day I pulled the radio out and the little orange wire was arc'd to the steel frame around the radio opening. So dont forget to tape up that wire.

glad you got it fixed Sean.