brdavis

i have a 03 2500hd 6,0 gas and i had just recently had the battery go all the way dead and tried to charge it but since then i am having idling problems. when im driving down the road it runs fine wbut when i pull up to a stop sign of light it boggs down and the ac acts up and get warm. i thought i was having charging problems so i went and bought a new battery and an alternator. stil nothig. i read on a older post that said if u disconnect a battery that the computer gets all wierd and does not know how to act.??!! is this true?? what do i need to do please help.. its making me go crazy!!! ha thanks!!