Billyboy746

I have a 1970 Cutlass Supreme with a 350 engine. I may need to replace the alternator. How do I find out if my alternator has an internal regulator? Is there one alternator brand that is better to use?
They seem to range from under 100 to 150 and over 200 bucks. Looking for suggestions.
Thanks,
Billy

MDchanic

What's wrong with the alternator? Why not rebuild it? The parts a whole lot cheaper than that.

Your car should have been externally regulated, but take a look at the firewall and see if you've got a regulator.
Also, the plug-in wire on the externally regulated alternator has terminals that go like this: ( | | ),
while the internally regulated plug goes like this: ( — — ).

- Eric

Billyboy746

Thanks Eric or the info. Couple other questions. The engine was rebuilt 3 years ago and has installed a new Red Top battery. There had been an interior light left on for 3 weeks and killed the battery.
I jumped the car and drove it for 45 minutes. I think that should have charged up the battery. Could it be the bad alternator or a bad regulator....if not inside the alternator?

MDchanic

It could be a lot of things. You won't know which until you troubleshoot it systematically.

- Eric

stellar

AGM batteries are a bit finicky when being charged especially if it was very low on volts. You may want to do research on the way to charge AGM batteries. I think it may only need a proper recharge. If you don't have access to a high tech charger for the agm, you can recharge it with any older charger if you connect a common lead acid battery in parallel with it. Charge both batteries until almost full and then you can remove the lead acid battery and top the agm off alone.