69 dart, added a/c and electric fan, and 100 amp alt. car will die at red lite if you sit to long with a/c and electric cooling fan on. feels like the car looses electrical to engine, but will restart.

Increase the idle speed a couple hundred rpms?
Is the Alt out put as good as it should be?
The AC tends to slow down the engine rpm, so bumping it up a bit may solve the problem.
Most high amp alternator still need to spin at a higher rpm to charge at full capacity, but maybe yours is not putting out as much as it should. I am assuming you upgraded the car wiring and the voltage regulator when you installed the 100 amp alt., if you didn't that is probably your problem. Gene

thanks i did not upgrade the regulator

engine still died, until i replaced the coil, driving two days and engine still runs

Success

But you may still want to look at the wiring. The factory wiring was only rated for about 50 amps or so. Some fans by themselves can pull 40+ amps. Keep in mind there are a ton of unknown variables involved on our part

ok thanks guys