[RonAckerman]

I just had an argument with my car dealership concerning a starting problem with my car. They were saying that as long as I had 12.8 volts the car will start. I said that having 12.8 volts isn't enough that I had to have the amps behind it or it wouldn't start. They said that the amps didn't make a difference.

I hadn't had any problems with the car since I got it until today. This morning I noticed that that it was rather slow starting, I drove about 20 miles to work using the radio and lights. At lunch time the car wouldn't start. After getting a jump start at quiting time I drove the car about 25 - 30 miles to an auto store and had them check the system. The store employee said that the voltage looked fine but thought the amps were a low comparing idle output to 2000 rpm output. Said the alternator diodes checked good and seemed to think that either the battery wasn't getting enough amps or the alternator wasn't sending enough amps (don't know about this theory), however the battery appeared to be good. When leaving the auto store I couldn't start the car again and got another jump start and drove about 5 miles to my dealer. Of course they jump in and it start fine everytime for them and I didn't have a problem the rest of the evening.

Here's my question and my take on it. What is starting my car, Amps or Volts? It is my contention that if my voltage is 12.8 volts but my amps are low the car wont start. Which is what I think we were seeing. If voltage is low (a more serious problem) then naturally the amps will be low too and thus it wont start. The voltage can drop but as long as it has the amps the car will start. Are there any automotive and/or electrical engineers out there that can support this theory?