Fuse box under the hood
 

I just got a 99 blazer lt and the fuse box under the hood has no power unless there is a wire goin straight to it from the battery. If you unhook the wire then you loose all power through out the truck. Could there be a short in a wires that connect to the bottom of the box? Any help is great thanx.

Yep, that is how it works. Where else would the fuseblock power come from?

If you have a problem, tell us. Are you saying it doesnt work without a kluge wire to the B+ stud on top? If so, look at diag, replace that big fuse.

O ok thanx. I figured it had a power wire in the harness the connects To the bottom of the fuse box because it is a 6 gauge speaker wire that is ran in front of the radiator to the box.