Engine Hesitation on 2000 Sierra

[mwkipf]

As of late I have had some interesting things happen to my car. About a month of go I lost the alternator and battery and had them replaced. After that happened I was still getting occasionally, the idiot light for a battery charging system problem. Only thing is, it would only happen when I was running my AC on MAX blower and MAX AC. So I thought, after careful inspection of my serpentine belt, that changing that would help immensely. My old one had 131.5K miles on it and was OE. I did this last night. I then proceeded to check and see if my voltage would drop when I turned on the same condition listed above. It did not when I was in Park or Neutral, but when I was in gear, the voltage gauge would drop from it's normal running range.

 

As I was driving to work this morning I played with the HVAC systems some more. I noticed with Max AC, my truck would have some hesitation at the start, but the minute I turned it off, the hesitation was gone and the truck was fine. When I would run normal AC the truck was fine, when I ran the heater full bore, the truck was fine. It seems as though MAX AC has a pronounced effect on my engine. There is an auxiliary belt that runs my AC compressor, is it possible that this one needs to be changed as well and that it could be the source of my problems? Or is there something far more mischievous at work here? I am still getting cold air out of the AC and Hot out of the Heat...I am severely frustrated with this, so any input you may have would be greatly, greatly, greatly helpful!

[GM-Tech]

The only difference between MAX (assuming you mean recirculate) and normal is that a door either opens or closes in the hvac case. There is no way this can have an effect on the engine.