just recharged ac in my 84. when i switch it on, the voltage drops to around 11 volts. belt is good and tight on alternator, runs high 13 other wise. if i unplug cooling fan and turn on ac, no issues with voltage drop. fans turns smoothly, and resistor had been removed from fan wiring, not sure what happens when fan kicks on when up to temperature. any thoughts?

Normal for me. If it is draining the battery and leaving it without a charge then maybe your alternator or corroded wiring?

The fan definitely draws some amps.

Charlie