One other thing. The voltage reg has to be grounded. It sits on three rubber isolation pads for shock absortion and should have a short ground wire. If it's on the radiator core support, you need to check the voltage from the neg bat post to voltage reg and also from neg bat to the core support. The core support is the ground for the reg and also the headlights. The core support sits on two rubber donuts, is bolted to the fenders and they are bolted to the cab with some old rusty bolts and the cab sits on rubber pads. If the battery ground cable has an extra pig tail, then that is bolted to the core support, if that is where the bat is. What truck???
