I have a 99 Blazer that is 4 Dr and 2 wheel drive with the 4.3 V6. A/c won't blow cold air and used to very well and I am now noticing a subtle whirring noise coming from the enginve when I accelerate. All my gauges are normal - heat, charge, tac. If you can't already tell I know nothing about cars. Any insight you guys could provide would be most appreciated.

Blazerkeeper

 

first place I'd look is the a/c compressor clutch if you're standing infront of the vehicle with the hood open on my 95 it's the top most left hand pully... (closest to the battery)
start the vehicle and walk around the front and then look at it with the a/c off you should see the pully flyin' around but you'll notice the inside isn't turning... ie. the compressor itself isn't turning... now.. have someone hop in the truck while you stay out there and watch the clutch have them pop it on Max A/C and fan on high....you should hear a VERY noticable "CLICK" and see the inside of the clutch turning now... and it shouldn't be slipping... sometimes the magnets in the clutch will get weak... and will snap shut but won't have enough *** to hold it from slipping....after you test that you might wanna also stuff your nose down real close to the clutch and smell it... ENGINE OFF of course... sometimes you can smell a burning smell if the plates have been slipping or even an electrical burn smell if the magnets have **** the bed on ya....