I am new so I apologize if this issues resides in the forum somewhere, but I could not find it using search. I have a 98 Blazer, apprx. 93K miles with V6 vortec engine. I have climate control on this. Just recently it started making a noise like something is acuating (moving from one position to another and back) all the time. (kid of groans). And the heat would go from cold to hot and repeat this process continually. This would happen no matter where the temp control was set. Now it I seem to only have HOT although I can still here somthing moving. BLower seems fine all controls for defrost, vent, floor, etc work.

THis all seem to start when I had an issue with bad battery and had to jump it a couple times before getting new battery put in.

I recently replaced the thermostat a while back when I put in a new waterpump. I worked fine for seveal months after that.

Thanks for the help.

 

It sounds as though you need to reset the climate control computer on your truck.

I believe that on a 98 you just need to pull the RDO/BATT 15 amp fuse for a minute or so and then reinstall and turn on the ignition.

If the reset does not work then you probably have the blend door actuator itself that has gone bad. There is most certainly a ton of information on that problem floating around these forums as it is a very common problem on these trucks.

 

Ok. I wioll try that. I did try removing the battery cable for a few minutes and replacing it to 'reset' whatever systems that might reset, but that did not work. Do you have to remove half the dash to get to this actuator for the blendoor? Is it a beer and a couple hours or a 6 pack and an afternoon? thanks