What is the voltage regulator for and do I still need it?

Well, not to be a smart a$$, a voltage regulator regulates voltage. There I said it.......... it prevents the charging system from overcharging the battery. I may be external (original on your car) or internal, (if someone has replaced your original alternator with a late model). If you post the numbers stamped on your alternator, someone can tell you if you still need the original "external" one.

Thanks for the answer. And, no it was not a smart a$$ response. I just bought a 140 amp one wire jegs alternator. I still have the original one in my car with abunch of wires on it. I was just wondering if I still need it or not?

Somewhere here on this site is a simple wiring modification to go to the single wire alternator.

here on this site is a simple wiring modification to go to the single wire alternator.
http://www.chevelles.com/techref/ftecref14.html
:)

1. A one-wire alternator is NOT the best system. You cannot drive the indicator light on the dashboard; and it won't compensate for high resistance in the 40-year old wiring harness. I'd avoid a one-wire like the plague.

2. Why do you need a diagram for a one-wire alternator? CONNECT THE OUTPUT WIRE, tape up the two-wire plastic connector from the old alternator so it can't flop around and short against anything, disconnect the molded connector at the external voltage regulator, and you're done.

I just did the CS-144 140 amp cop car alternator for my '70 yesterday. It's from a '96 Impala 350. Since time is money, I bought one of M&H's CS conversion Forward Harnesses and have a plug-and-play solution. No screwing around, no guessing, no shorts. Now I'm rock solid at 14v at idle with the brights on :thumbsup: A 40-year-old alternator harness needs to be replaced anyway. Now that it's out of the car, the old one looks spooky.

With all that's been said about the short comings of the one-wire alts, I don't know why they are so popular.