I've got an alternator that was originally purchased from Hervey many years ago. I've had three of them installed. I have a ground bus installed. And yet, when my engine is idling, none of these alternators have been able to maintain a nice output if I have the lights on or the A/C on. They all drop voltage, my lights dim, air motor slows down, until I push the accelerator to give me 1,000 RPMs then the needle bounces up and all is great. I have DPI fans, and even have my ECU programmed to bump the RPM up by 100 (850+- Idle RPM) when the A/C turns on yet I still have this issue. With no accessories turned on, my engine idles at 750+- and the needle is pretty steady with a good voltage.

It's been an annoyance from the beginning of ownership that I'd love to finally get resolved.

Can anyone tell me their experiences with other alternators? DMCH? Saturn alternator?

Thanks in advance