dash lights and marker lights fuses keep blowing

[Austin idi 7.3]

my truck is a 91 f-350 an it's curent problem is that the to fuses that run the bash light and marker lights keeps blow it's blows both of them as soon as i pull the light shwich on but my head lights still work could i need i new light switch??? or do u think the a wireing problem

 

[snicklas]

I had this happen on an E-150 Van, there was a corroded connection in the trailer harness at the back of the van. Blew the fuse that ran the running and dash lights.... Just a thought.....

 

[MIDNIGHT RIDER]

my truck is a 91 f-350 an it's curent problem is that the to fuses that run the bash light and marker lights keeps blow it's blows both of them as soon as i pull the light shwich on but my head lights still work could i need i new light switch??? or do u think the a wireing problem

Ford was really stingy with the quality of wiring in these trucks.

Look at the big *** of wires coming out of the fuse-block and see that the light-tan wire has burned itself out of it's insulation and is now against a GROUND.

 

[Sycostang67]

The tan/white wire from the headlight switch likes to melt and could have contacted a ground as mentioned. I've had that issue on a couple trucks now. Also check the wiring from any extra lights that may have been added as well as trailer wiring like previously mentioned. If the headlight switch is going bad, it's usually the headlights that will start going out.