I have 2000 Chevy Blazer 4.3 V6 with A/C problems.
This model has the Electronic Climate Control and when I bought it the heat would not go off and the compressor would not start and the vent controls would not work>
I replaced the the Electronic Climate Control. All the controls worked as normal except the compressor was not getting voltage and not coming on. So as my friend and I were trying to figure out why the compressor would not engage. there were 3 or 4 pops under the dash and the controls began to blink. I pulled the dash and moved the actuator the light stopped blinking but now i'm back to heat only. What could the problem be. I'm out of ideas with this fancy control that don't work.

 

having a similar problem on my 1998 Blazer. I just haven't changed the climate control unit ... i tore apart the dash but still don't wanna spend the cash til I'm sure. Hope ur having better luck

 

After days of research, and subscribing to all-data d.i.y. I found the problem. There is a simple test you can do to confirm where the problems originates. And save lots of time and money. Its not hard to do and can be done in less than 30 minutes.
1. Disconnect battery cable.
2. Open glove compartment, and lift tab in upper left corner to allow the glovebox to swing down completely towards the passenger floorboard.
3. Gently remove the line that enters the "Vac Unit", and then the "Vac Unit" itself by wiggling it upwards off its mount. Once removed gently swing it towards the drivers side and out of your way.
4. You now have access to the Temp Actuator.
5. Carefully remove the electrical connector that feeds the Actuator.
6. Using a 1/4" drive wratchet, and 7/32" socket, remove the two (2) mounting screws. (HELPFUL HINT: For maximum ammount of clearance, Keep the wratchect handle facing the drivers side when putting it in place.)
7. There is no screw on the back mounting post, just a pin that holds it steady.
8. Once you've removed the screws you may need to gently pry the Actuator up off the blend door with a screwdriver.
Installation is reverse of the Removal. The Blend Door and Actuator are both keyed, so theres only one way to put it in. Guide the Actuator onto the Door, then re-secure the mounting screws.
9. To be positive its not the control unit. Turn the engine on leave the unit plugged in and and turn the ac on. If you can feel a clicking in you hand its NOT the control unit. Take the 4 little screws out and you will see that the BIG gear has a crack. replace that and enjoy your a/c and heat once again .
I've had the Blazer for a little over a week. Not totally happy with it, but its got potential! :-) I will be happy to share pics or whatever you need with this process

Did you get ur problem resolved?