99 Mailibu shut off while driving

Hello,
my wife has a 99 chevy malibu that's had some problems lately. First, it wouldn't start one day, eventually figured out the battery was bad and replaced that. Now, the battery light has been coming on the last week or so, but I know the battery is fine (less than 2 months old now). Now, she was driving home and the light started flickering, as well as the clock on the radio was flickering, then the car shut off (luckily she was just a block down the street). So I tried jumping it so we could drive the car home, and we could get it started but it would turn off within 10 seconds. It sounds like an alternator problem to me, but I'm no car expert at all. Just wanted a second opinion, and also wondering how hard it would be to install a new alternator. Also, the car has about 115,000 Miles on it. Any help would great, Thanks.

Based on the description of the symptoms, i would concur that it is an electrical issue, but it may not be the alternator. Check the serpentine belt first. Start the engine and verify the belt is turning and the alternator is turning. If thats is working fine, then its most likely a faulty alternator. Replacing one isnt to hard as its right up on top, but tentioning the belt can be tricky. Unless you are really bent on saving some coin, it might be better to call a shop (AutoZone or other parts stores sometimes have onsite garages), charge the battery for about an hour, then drive the car there.

What exactly is the serpentine belt. I'm assuming its viewable by just opening the hood, but I would be lying to say if I knew which belt it was.

Its the main belt that runs just about everything on the car. (Older cars used to have multiple belts, but now a days there is just one belt, and because of the way in snakes around to get to all the pulleys, its called a serpentine (serpent) belt).

One other thing to check, you didnt say the lights were dimming, just outright going dead. You might want to check the positive battery cable. If the power is there, then just gone, and back again with no dim headlights, you might just have a corroded positive cable.
A couple of years ago I had the positive terminal on my battery corrode out and the acid did a number on the cable as well causing me to have to replace it as well.

Cool thanks for the help. I'll look into this after I get off work tonight and let you know how it goes. Also, to clarify on the lights, when we had the keys in the ignition the clock on the radio was constantly flickering. It wasn't all the way dead, and also the day lights of the car we're still working.