stopped working, and i dont know why!!
 

hey guys got a 97 blazer and the heater/ ac doesnt work i thought it might be the heater control unit so i bought a new one and put it in still dont work so what do i check and how do i check it and where is everything located where is the blower motor located and how to i take it out?

as much as you are not going to like hearing this.... that sounds like a bad/plugged heater core. that means you have some good times in your future....

search it up, there are walk thru's talk thru's and how toos. <-- I'm Dr. Suess!

Well, lets get some things straightened out here first... When you say that your heater/ac does not work, what specifically does not work? Does the blower work? Is that the actual issue or is there more to it?

the blower doesnt work at all, after it gets up to temp going down the road i can feel a little hot air come out of the defrost but it has no force behind it so i thought it might be a blower issue

Is the blower motor inoperative at all speeds? If so, you'll need to check the related fuse and relay.

This diagram might help:
http://i11.photobucket.com/albums/a1...blower_sch.gif
It's been posted before.

where is the relay located and how do i check it?

for a quick and i mean "quick" fix possibly, you can pop the hood. on the passenger side near the windhshield under the hood you have your blower motor assy. (its a black plastic box snug fit between the fender and the firewall) with the side of your fist give the box a bump and it may kick on..