Volvo: Volvo 240 lights flickering, volvo 240 dl, 1989 volvo 240

Question
Have a 1989 Volvo 240 DL.  The lights work fine when ignition key is in but not started.  After I start the car, the lights flicker as if the power to them is not constant.  Don't go off, just dim and come back, dim and come back - they flicker constantly.  So do dash board lights and interior light.  I am about to replace the alternator.  Anything I should check before I do that to possibly save some $$ by not having to buy a new alternator?

Answer
It defintely sounds like the alternator.  Besides the unit itself failing and needing to be replaced, sometimes the belt can be loose and slip, causing partial power.  You would probably know if the belt were slipping, though, because it would make a horrible squealing sound.  Mostly likely just a dying alternator, especially if it is original.