I have a 94' s-10 blazer tahoe LT. The 4wd, the rear window wiper, the rear window washer, and the rear window defogger do not work. The switches don't even work. I noticed that the radio fuse was blown even though the aftermarket radio was working. (Found out that the radio was wired in for power from a different wire.) I replaced the fuse and went to start the vehicle. The 4wd switch lit up and then it blew the fuse again. Any ideas on what might be the reason for this? I am about to dig into it but, maybe someone has been through something similar. I had it diagnosed by a shop through and they said they couldn't find anything by way of the diagnostic port. Any help would be greatly appreciated!

 

It's a 4.3L vortec engine code "w" if that helps

 

Sounds like you might have an electrical short somewhere, which is probably why the radio was wired differently.

 

Does anyone know what is wired to the radio fuse? I know that it is the radio, something with the 4x4, the rear wiper, and the rear washer. I have a haynes book but, that thing doesn't give a lot of information as far as wiring on a push button 4x4.

 

Another thing to check is if the radio has 1 of them universal wiring adapters cause I have seen them things cause all kinds of problems but usualy with the headlights and stuff

 

I'm still having this same problem. Does anybody have a wiring diagram that includes what is on the radio fuse? Or does anybody have any idea what may be causing this?