needs to be grounded
coil needs to be 8v coil with correct primary resistance paired with a ballast of correct resistance. these two added togther must limit current to 2-3 amps
regulator should be electronic rather than mechanical
AND
if you are running a big battery of capacity and cold cranking amps way higher than the original, it will maintain 12 volts and start the car perfectly well even when quite flat.
a Stall.
At pulling away RPM (1000-1500) with the alternator in Full-On Charge-mode, due to flat-ish but big battery.
You see your ammeter pretty much pegged to the end stop after starting the car. And then you stall it. cold weather, siezed brakes or snow bound wheels, tyre up against curb etc etc
The back EMF SPIKE from the coils in the alternator, when it stops abruptly, can take out the module...especially if the condenser is marginal or burnt out
even more likley if running a GM HEI 4 pin.
they can only put up with this once or twice
having bust two modules on two seperate visits and in the same manner i'm pretty convinced that this is a "thing"
Trying to drive my car backwards out of the same hole in the camping field at the track
i'm pretty convinced this plays a big part
on both occasions the car battery had been charging everything from phones E-cigs and blue tooth speakers the night before. Hung over, needing bacon and eggs and coffee, on a wet miserable morning, on a disused WWII airfiled in the middle of the UK, K frame resting on the mud, Yes i can stall it on an incline in long wet grass
i carry a spare
Dave