Electrical Probs

[Numba1Sean]

ok well here it goes, been having electrical probs for a long time so far. so i did the basics: thought it was the battery so i went out and bought a optima redtop, a little bigger then what my suv calls for, this was a no fix. so i went and did the big 3 in 1/0 gauge and i have minimal if any resistence in the grounds and the stock ones seem ok to the eye, also checked the fusible link for a break and nothing, this also did not help. so i went out and bought a new alternator cuz i thought the stock was maybe shot, so then thinking well i just got a rebuild and not everthing was new so i said the hell with it and had the guy put it back to stock and then bought a brand new 220 amp, this did not fix the prob. replaced belt tensioner and belt also, no fix. i took my cap out to see if it was bad, and i believe it was because it took less then a minute for the thing to completely drain out. ok well i pulled the plug<-- fuse, on the amp to see if it was drawing somehow even when off. now my radio flickers when i have it up to a certain volume, does this mean the radio is on its way out? yea so also my dome light flickers when its on and where my mileage and gear selector they flicker. i basically did all this because i was getting some nasty voltage drops. i checked the battery and it was reading 12.1 with the car off and i thought this was a little low, so i threw a charger on it and it charged up to 12.8 nice and easily. didnt drive it at all that day, started the next day with my remote start, and when i went outside my tailights, headlights, and all dash lights were like strobing. so im not sure what the hell is going on with this, and not to mention i was only running maybe 500 watts rms. i think i can pretty much rule out the alternator by now, but not sure about the battery cuz it wont stay above 12.1. but when i start it i get 14.8 to 14.9 at the battery until it warms up a little then its 13.8 or less or sometimes higher depends on what it wants to do and this is with nothing on.

by the way this would probly help: 1998 chevy blazer ls with the 4.3 v6.