Hello all, I am a new member here on the forum. I own a Mazda Protege ES 2.0L. Anyway I have having problems with the electrical system. I will be driving and suddenly the nonessential electric components (radio ect) cut of, and it shifts out of overdrive. Then the battery runs out of power and the car quits. We tried replacing the alternator and battery, but it still has that problem, and it seems that something shorted out the new alternator. What could be causing this? Was the new alternator simply faulty or is there another problem somewhere else?

Thank you all so much!

 

Depending on what year it is the voltage regulator is in the PCM, not the alternator.