I currently have a 99 blazer and i have 2 problems atm with it. first one being its starting to over heat. I thought about replacing the water pump which i hope is the problem and not a bad block. If was leaking from the block where exactly would it be leaking. and second my heat doesnt turn on at all nor does my ac. I recently was going to fix the ac and i came to the evaporator nut that would not turn so i screwed it up and i havnt yet had i chance to take it in. so i left everything off and just left the compressor on as a pulley. i told you that because before i did all that my heater worked fine. maybe it could be a fuse. if so which fuse it since there all abreviated.

 

99bb99-Too many scenarios regarding an over heat issue:bad water pump,faulty t-stat,system in need of a good flush and external radiator cleaning,the dreaded lower intake gasket failure.The fastest way to a solution is a pressure test,that will determine cooling system failures where they may be,simple procedure. As to your loss of heat and A/C,since it was sudden is probably vacuum related...when you started to pull things apart,did you miss an item putting it back together? Was the A/C working prior to this issue? See what I mean? Too many possibilities to internet fix w/o more info...

 

well good news is the leak is from the water pump. with the heating and ac i dont have any of the hoses hooked up and nothing is connected to the evaporator because i cant get the nut on the evap to turn so i have to get it replaced