I go out to start warming up my car the other night and when I go to start it everything dies. Stereo, lights, warning lights. Everything. Dead in the water. I have 12.5v at the battery and I replaced the 80A main fuse.

What can I do to track down this electrical issue. Could it be a ground? If so which one would cause a complete failure?

Any help would be much appreciated.

Also when I replaced the main fuse, I measured the voltage coming off the two wires and it went from around 12v and dwindled down slowly to around .25v, is this normal?

I really need to get this car up and running as it is my only source of transportation.

Thanks in advance.

 

Check grounds, also check to see if the battery cables are corroded.

 

Voltage coming of What two wires?

Do simple things like the headlights work? Side and tail lights work?

No headlights or tail/side lights indicates no power getting from the battery to the engine bay fuse box from the smaller of the two cables attached to the Positive cable on the battery.

IF you do have side/tail lights and headlights..........indicates no power to the ignition switch from the engine bay fuse box. THAT power feeds power to half or more of the interior fuse box which in turn powers the items in your first post.