Oldsmobile/Buick Repair: battery charging, buick park avenue, 12 volt

Question
Thanks a lot for your help:
I know battery should be charged at 13 or above volt.  
but the battery of my 92 Buick park avenue is some time being charged lower than 13 or even 12.2 volt.  Is it normal?  They are a new battery and a new alternator which included a new regulator.
when connected to the old alternator, sometimes goes even below 12 volt.  it caused a jump start once.
Someone suggested to me it was the starter but I really dont see why.
There is a motor under the right side of the hood ofen runs.  I think it cost a lot of charge.  this motor runs for 3 minutes after the car turned off.  Someone told me it is a suspension leveling motor.

Thank you


Answer
Hi Ken,
That probably is what that motor is. But it shouldn't pull the battery down that far.
I think a loose or corroded connection somewhere.
I have also seen some side post batteries not making good contact internally, but that is very seldom.
I would check the wire from the alternator to the battery, which could go to the starter stud.

Van