MSD 6AL #6421.....For some unknown reason, I have 12V at the negative (black) coil wire, and when it's hooked up to the coil, then I have 12V at BOTH terminals. Needless to say, the car won't fire. It was running fine yesterday...I've done the check by unplugging the distributor wires and bridging them...no spark. New coil...no spark. Did my MSD go south???
I have power, key power and ground is good.