GoGibbs

Alright, I'm hoping someone can help me with a problem I'm having. I parked my 1990 1500 4x4. Everything was working fine when I parked it. I went back two days later and nothing electrical is working. The battery has 12.5 volts. The ground wires are good from battery to engine block and frame. I have a good ground everywhere I check. The only thing that is working are the lights. The lights come on fine. It seems that any circuit run to the fuse block is not working. This includes things that should have power all the time, like door locks. At first I thought it might be the set of contacts on the steering column that move when you turn the key, but the door locks and horn, etc, are not working either. All the fuses in the box are good. I do have 12 volts at the fuse box, at least on a few of the circuits I tested. My only thoughts now are the fuse box itself burning up a hardwired path on the board, or if there is some kind of "master fuse" or a fusable link that I'm missing. I'm not an idiot when it comes to electrical issues, and I have a good multimeter, so if anyone can try to explain what might be going on, i should be able to fix it. Thanks for any help!

GoGibbs