Engine dies when lights or any electricity is turned on

[WadiaAbushanab]

So I just recently put a new distributor in, and started noticing this issue. Not sure if it’s related or not.
Anyways, if I turn the lights on or the dash lights, the rpm’s will drop down low and then jump back up and do this repeatedly until it dies. This also happens even when I’m not pulling electricity from anywhere, just at idling normally. Once it dies It also has a really hard time starting back up to the point where I have to hold the gas at idle for a bit. I think maybe it’s the alternator? Any ideas?

[spider2081]

A 1980 Fiat Spider can be carbureted or Fuel injected depending on the month it was manufactured. Is you Spider Fuel injected?
How was the engines timing set after the distributor was replaced?
An alternator is a physical load to the engine when the alternator's shaft speed is 1000 rpm or higher so at engine idle rpm most alternators are putting out some power and loading the engine.
Is the battery charge light lit in the tachometer when the engine is running?