I was having the same problems on my car. I have three older style Autolite reproduction regulators and with each one the alternator light stays on. If I raise the Rpm on the engine to about 2000 rpm the light goes out. The concourse correct reproduction regulators have lots of issues. I bought a fourth regulator over the weekend and finally got a good one. Light is off and car is charging perfectly. I would return it to wherever you bought it for an exchange. Especially if the one you took off of the car is working properly. I’m sure wherever you bought it from is well aware of the issues people have with these things.
