Still learning about this car, but my idle once warmed up drops from 800ish to 600 when you turn on the headlights. The PO installed some halo led headlights and not sure if they could cause this. I know the original 12A alt is not strong, but seems like a big drop.
85 GS
All stock
All new cables and grounds
Also additional wire from battery to alt.

I'm a little concerned since I will be adding a/c next month and that might kill it.
Thanks

 

Idk FBs very well, but FC its normal. If your really worried about it, upgrade your alternator