Oldsmobile/Buick Repair: buick idle solenoid motor, power steering hose, air cond

Question
REF" 1985 buick century
    3.0 /2 brl carb

I would like to know, how this solenoid motor operates. I have been told its activated when the ignition is turned on,and remains on untill the ignition is turned off. I have also been told it is activated each time a load is applied, like air cond,or elec fan etc. This would raise the RPM so stalling won't accure. I will stall if i turn my wheel left or right, while sitting still, or engaging trans in reverse,while sitting still.

I would like to know what controls the R.P.M and prevents stalling under heave loads.  

I look forward to your reply.  

Answer
hi paul.well here is the story on the iac true when you turn the key on it is activated.as in  5 volts are applied to it but it also is controlled by the computer there is a sensor in the high pressure line of your power steering hose.but the computer determines when the idle should raised.if it is not raiseing the idle properly most likely a bad iac sensor. please take a min to rate my help ty billymac