Mitsubishi Repair: alternator, pulleys, hesitation

Question
I am have a JAPANESE 1996 Mitsubishi FTO GR(MiVec Sport), Automatic and last night the car would not turn over, i had it jumped and it started, however the battery was reading 4V not the normal 13.9 it does every so often on my drive home it would read 13.9 then 11 then back down to 4.  The batter was replaced in July of 2005.  The alternator and everything else is orginal to the car. I have 72000 KM (about 50000 miles) what are the signs it is the alternator?
Also, my serpintine (spelling) belt was squealing for a while, could that have been a problem?

Answer
Stacy,
Your battery should be fine.  But you are describing symptoms of a failing alternator.  Alternators usually die slowly.  Some signs are stalling, hesitation, and your radio and other accessories may turn off by themselves while you're driving.

But a slipping drive belt (that's supposed to be turning the alternator) can cause the same symptoms of a failing alternator.  You can have the belts changed first to see if that helps. The idler and tensioner pulleys should also be inspected. If that does not help your problem, replace the alternator.  
Good luck!