I am having problems with my 2002 S10 climate control. The fan works fine on all speeds, the temperature blend control works fine, but the mode control does not work properly. It seems to be okay in the vent only position, but when I try the floor/defrost or the defrost only positions, it does not switch to those modes. Some of my research on the internet seems to indicate that it is controlled by vacuum actuators and some of the research indicates it is controlled by stepper motor actuator. Does anyone know for sure? Can anyone tell me where these actuators are located and how difficult it is to replace? ANY AND ALL HELP WILL BE GREATLY APPRECIATED!!!!

I am not sure if they are electric or vacuum but if you take the glove box out and the lower hush panel on the right side you should be able to see the actuators. If you find they are the electric, which I think you will have, most of them were the same and you may be able to switch two of them around and see if that makes the defrost work. If it is the vacuum system and it has a leak then it should default to defrost. I have seen pencils and other foreign objects go down the defroster vents and block the doors from working.

Okay, I've done some work to help with the problem that might trigger someones thoughts on what the problem might be. I took out the center console and a few of the lower panels under the dash. With everything turned off I can hear the clicking of an electric blend door actuator, but I don't really have a blend problem. Now looking under the dash just above and to the right of the accelerator pedal are two vacuum controlled actuators. One of these actuators has blue and red vacuum lines coming from it and the other actuator has yellow and brown vacuum lines coming from it. Both actuators move when the climate control knob is turned, but I'm not sure if they are moving sufficiently to make my defrost actually work. The actuator with the yellow and brown vacuum lines has what looks like some rust on the rubber where the actual actuator arm comes out of the actuator and the actuator arm seems to shudder when it is moving inward. Can anyone tell me if this might be the problem (the actuator arm may not be moving inward completely), or if in fact this is the right actuator to be looking at for my defrost problem? I WOULD REALLY APPRECIATE ANY AND ALL COMMENT AND ADVICE!!!!

I did have a 2000 S-10 V-6 Extreme which I gave my granddaughter when she graduated from college. When I first purchased the truck new I had troubles with the heating cooling system. The dealer removed the complete dash and all the heating and cooling components and checked each one individually. They could not find anything wrong, however they decided to make some holes in the air gate to try to solve the problem. This ended up with a shrill whistle anytime the unit was turned on. The dealer removed everything from the dash again. They consulted with Chevrolet and the net result was that it was just a poor design. The truck still has the same problem. I have a second 2000 S-10 with the 4-cylinder engine. The system works very well on the second truck.