My 99 Blazer has the electronic climate control system. It is blowing hot air at every temperature setting. Better warm than cold I guess since it's winter here in Michigan but it's roasting me out of the cab!

I had a new heater core installed the same time the radiator was replaced last spring. Research leans towards a few things like temp sensors or the electric motor on top of the heater box that controls the damper door.

What do you guys think as a first step or suggestions.

Thanks!

Also,The AC in this vehicle does not work and has not for a few years, just thought I'd add it in even though probably not related.

 

im assuming that you are talking about the climate control that is all automatic right? if so try this:

Key ON
Engine OFF

wait for the "beeps" to quit

when its all nice and quiet, sit in the passenger seat and change the temp on the **** from full cold to full hot or visa-versa

you should be able to hear the blend door motor make noise. it might take it a second to start making noise but you should hear it. it might help to pull the glove box down since its behind there and a little to the left. its not very loud, thats why you need the engine off.