Wierd electrical problem. gauges go nuts and truck shuts off

[hurst1979olds]

I have a 2000 4.3 5spd 4x4 base model. Crank windows, manual locks, no cruise and had factory tape deck only. I installed a Cd player a day after I bought it and Ive owned it for 4 years. When driving my volt gauge moves alot but still charges when check at the battery at 14.2. Then all of a sudden everything goes nuts then the security light starts blinking and the truck seems to be still running but nothing happenes when I hit the gas. I shut it off and turn it back on and everything is fine. Just recently everything goes nuts and goes back to normal but my radio turns off and turns back on like the truck got shut off and turned back on. But I just noticed the battery light will blink before everything goes nuts and sometimes after it goes nuts. Sorry for long story buts its alot of info. Any help is greatly appriciated

[suicidal]

...time for a new battery.

[hurst1979olds]

When trying to diagnose I checked and replaced as listed even though it wasnt bad but just for sh**s and giggles:
Battery (under manufacturer warrenty)
Alt (under manufacturer warrenty)
battery cables pos. and neg.
check all grounds
everything checks out fine and its got me nuts