I am not 100% sure but it may not be your voltage regulator as the old cars had them I think on the firewall and were known for going bad in the old cars. Just start the car and touch the red alternator wire with a voltage meter and turn the ac on. See how many volts it puts out. It is either a bad alternator when it has a load on it or a bad regulator. The battery won't make the car die out while running. The car runs off the alternator when running not the battery. To prove it, Start the car and disconnect the battery cable while its running. The car will stay running off the alternator even though no battery is connected. I am willing to bet the voltage regulator is bad and it isn't allowing the alternator to put out enough amps to keep the car running under a load. If not, the altenator has a malfunction short in it when under a load. Regulators new are $20 and install in 5 mins. Altenator new is about $65 for remanufactured and installs in about 20 mins. Best answer. Thanks :).

Sounds like the alternator isn't putting out enough to run the car properly.

Sounds like the alternator is going out. Or you need a larger one to produce more power.

Your mechanic is most likely right . It appears it is your battery. You can also buy a jumper battery , which you charge with your house electricity and it is about half the price of your car battery. Keep it handy , fully charged in your trunk.

I have a 1970 Chrysler New Yorker that I just got back from the shop. It drives just fine so long as I don't use anything electric, starts up without issue and everything every time. The minute I turn on the a/c though, or use the blinkers for an extended period of time, it's fine until I hit a stoplight. Then, after sitting for a minute or so, it starts to shake and eventually stalls out. When I go to start it again, it feels like it's barely starting.

So long as I don't use the blinkers or a/c, the issue is never there and the car runs great. I can idle for quite a while without issue. The minute anything that draws power is turned on, the car will crap out.

My question is, is this a battery or an alternator problem? My mechanic said I needed to get a bigger battery, but that's because he said I needed way more CCA's for where I'm moving (moving to Minnesota, current battery is a Valucraft VL24 with 550CCA's, mechanic suggested 1000CCA's). I just don't wanna drop money on a new battery if it needs to go to the alternator instead.