61 Buick. Was 3 wire alt...now 1 wire (I know I should have bought a 3 wire but the 1 wire came with the new front runner system, and I'm not changing it now as everything is in) I have a Ron francis low voltage sensor that can be wired into the dash charging idiot light. The RF kit says red to sign switch +...black to ground and blue to dash light. Then dash light to ground. I hate electrics I get so confused. So I assume that what happens is the sensor acts like an always off relay. When voltage drops below 11 volts it "flips" to on and puts positive voltage to the dash light. So what I don't understand is. In the old 3 wire alt way, the charge light would come on when there was no charge from the alt, essentially NO 12v source. But. does that mean the alt acted as a ground when no charge but broke the ground connection when there was a charge? So does that mean there was 12V coning out of the dash light not 12v going into it and that it only grounded when the alt wasn't charging. If my thinking above is correct then I can't just connect the RF blue wire to the dash light wire as there is no current ground connection to the dash light? Am I thinking this through right or am I completely confused?