Everytime i turn my A/C on (very rarely, ususally just for demist) my car will not run properly..

for example if i switch it on while idleing, the rpm will drop to below 500 and rise again, and drop again..and with that brings a clicking sound (a/c comp turning on and off?)

does anyone know why its droping revs and not picking them up with the switching on of the climate?

for memory, isn't there a solenoid that boosts the idle speed to compensate for the AC pump? Maybe thats the problem (stab in the dark)

isc could be dead. or the caps in the ecu could be shot. if its that, theres a thread on how to go about swapping them out