So I'm getting voltage in the body of my car, on the firewall and it sits in the grounds on my firewall and when my exhaust taps my firewall it sparks. There is about 7 volts. I notice when I removed the cable from the battery fuse box that traces down to the relay panel under the dash the voltage drops all the way to 1.8 v, though I have no idea where the other 1.8v could be from, and I did find a blown fuse down in the relay panel. Do these wires on the battery fuse box go bad often? Car will not start and getting fuel injector short to ground codes.