Alternator / Charging System 1988 325ic
I thought i was having a charging/battery problem so i took it to a shop. It was basically a brand new battery so i thought it was the alternator. Well after about 2 hours the mechanic tells me that it is indeed my alternator. Unfortunately the one they had in stock was defective and it would be another 30 mins before they could get another one. The new one arrives and is installed. A few hours later he tells me it might have to stay overnight. They said the second new one wasn't charging the system either. They said it passed the bench inspection but when they put it in, it still wasn't charging the system properly. Any thoughts to what it may be? I thought it was the alternator because i was driving at night and my headlights and stereo went out. The car kept driving with a dead battery though. I pulled over, turned the car off, and tried to start the car but the battery was completely dead. I brought my battery to the auto parts store and they charged it for me. Car started right up with headlights and radio. Could 2 new alternators with built in voltage regulators really be defective? He said that they would have to do some sort of complete car diagnostic test. They would search the car for any sort of electrical drain on the system. This doesn't make sense to me because even if the car has some sort of short or drain the alternator should still be pushing out the correct power, but its just not reaching the battery. The car can sit for days and the battery holds enough charge to start perfectly. Is this guy an idiot? Should i just give in and bring it to a specialist?