So I never payed much attention to it.. but turning on my headlights and just the fan setting (for air and heat) drops my idle considerably... like 150 or 200rpm. Is this normal or do I have a crapped out alternator or battery? 1990 22r also.

 

More than the likely your alt is crapped out.

 

Remove & clean all connections first; including ground wires & battery terminals. If problem still persists, you may have alt going out. They can be rebuilt to double OEM specs pretty easily at WAY cheaper than a new OEM.

 

You can also pick up a high output alt. for about the same cost as oem. Always thought was kinda weird.