Stall/Dies/Trouble starting

Hey guys/gals. I have a 96 Chevy Blazer. I am having some problems with it. It usually starts ok, except I notice the voltage pin is 3/4 to the max for a bit and then steadies down to the middle mark. As of lately, I will either be stopping or accelerating sometimes and all the dashlights come on and flicker as the truck starts to die. Sometimes it will just flicker and start on its own and other times it will die completely and I will have to pull over and start it again. If I know its starting to die, I try and run the gas and the brake at the same time to keep the voltage up and stop it from stalling. Today though I was driving and it totally died on me. My 4 ways wouldnt come on or anything. I tried to start it and nothing, was totally dead. I opened my truck door and all of a sudden the beepin came on, so I new I had power, I tried to turn it over again and everythign quit. The strange thing is when I took my key out of the ignition, it started make a weird buzzing sound similar to the sound it makes when you leave the keys in the ignition and open the door. Anyways, I ended up pushing it over to the side put my key in and it started right up, except everything was reset... my clock, radio.. etc.. etc.

Any ideas?? The battery is only 1 1/2 old and its a good one. Plus because my voltage is sometimes to high and sometimes to low I dont think its the battery. I was thinking it must be the aletenator, starter or voltage regulator.

I'd try the free stuff first. Clean the battery cables. You can pry the "bolt" out of the cable to access the inside of the cable ends and toothbrush some bicarb(Arm&Hammer) & water to neutralize any old acid and clean the metal. Rinse with clean water & dry.
I reassemble with a little all purpose grease to slow down corrosion & just brush clean the battery posts then reconnect the cables.
You might check the battery wire on the back of the alternator for tightness then give the alternator housing 1 sharp tap in case the brushes are stuck. If all this stuff fails, take the alternator to a chain type auto parts store and get it tested...free of course.

. . . The battery is only 1 1/2 old and its a good one. Plus because my voltage is sometimes to high and sometimes to low I dont think its the battery. I was thinking it must be the aletenator, starter or voltage regulator.
As has been said, clean the battery cables. I would also suggest getting the battery tested, regardless of age due the problem you're experiencing. AutoZone will do it for ya, for free. They will also check your alternator for ya. Even replace both for free on the labor if purchased there.