Hello all, I'm not sure if I'm doing this correctly because I'm new to this web site forum. Actually new to all forums haha. I could use some advice though so here is my problem. I have 1993 F250 4x4 7.3 non turbo that I love. I put 2 brand new batteries on it less than a month ago. Today I drove the truck and parked it with no problem but when I came back a few hours later to leave again and turned the key over no dash lights came on and it wouldn't start. No sound at all when you turn the key. No cab lights , no electrical power anywhere. I checked the voltage on the 2 new batteries and still had 12.8 on each. I checked the battery connections and they are solid. Im not a very good mechanic so im kind of at a loss. I had to replace the relay switch on the passenger side fender wall a few weeks ago but it has been running fine since then. I don't know if there is some kind of master fuse that may have blown or what. Any ideas would be much appreciated.

 

You're on the right track, there is a fuse link that powers the cab accessories that is part of the wiring harness that runs from the relay on the fender around the front of the passenger battery and goes all the way to the cab. I cant remember what color the wire is, but I had that same problem years ago and it gave me heck cause it would fail then work then fail and work... finally I found out the fuse link was cracked inside the insulation and cut it out and replaced it with a breaker.

That'd be the first place I would look, pull the passenger side battery and open the loom. Like I said my fuse link was cracked so it wasn't possible to see it visually, had to use touch to find it. There are 2-3 other wires in the loom with fuse links all right together FYI.

 

Ok thank you much, Ill check that out. So these fuse links are wires with something like an in line bus fuse?

 

It's soldered into the wire, it's actually a piece of wire set to burn out at a certain amperage. Normally you'll see it as a bump coated in rubber. Testing each side with a test light will let you know if it's bad.

If that isn't it I've seen the ignition switches separate before, pull the trim around the bottom of your collumn and then two nuts and the collumn will drop.

 

Ok thanks so much, Ill check that ignition switch 2nd this evening

 

Edit: Might be a fuse since there are no cab lights (missed this).
Is your ignition switch operating properly? Do you have a tilt wheel? Maybe the actuator is kaput?