Bad Grounds

[vintageracer]

Look at the wiring harness plug at the firewall. Remove the wiring harness plugs at the firewall fuse box on the engine side of the firewall and clean the connections. If the car is dead and a jump helps, corrosion could be the problem at these plugs. Also check the connection on the 12 gauge wire in the front wiring harness at the junction block on the passenger side of the radiator support and at the horn relay.