2000 f 350 when i turn on the lights i have no dash lights and no taillights, mini fuse #4 trailer lights; 20 amp is blown repalced several times, blows a fuse every time i turn the light switch on. havent been able to visually locate a bad wire . could it be the light switch, wich i have seen alot about on this site, or would it more likely be a shorted out wire some where? Thanks for any help

 

The trailer tow fuse being blown should not cause the dash or taillights to be out. I would check other fuses in the Power Distribution Box, and look for corrosion or signs of water intrusion in and around the relays. The trailer tow fuse being blown would seem to indicate multiple shorts.

 

You dont think the head light switch could be the problem ?

 

It's possible, but I don't think it's likely.

It's certainly not causing the fuse to blow, because the trailer tow wiring doesn't go through there. And, the fuse blowing indicates that power is getting to the trailer tow running lights relay, which would seem to indicate that the switch is working.

 

Have since found the problem it was a bad wire in the trailor towing hook up right behind the plug in .