2000 Sierra Heater Problem

[orange300]

Newb has question,

I have a 2000 GMC Sierra Z71 with 87k on the odo that has heater control issues. I have not pulled any trouble codes as yet as I'm not sure this system is monitored.

The temperature of the cab air stays stuck in a warm/hot mode when the selector is set even slightly above full cold. When returned to full cold it will not readjust the air temp down until the engine is cool or the truck sits for a while. Turning the A/C on makes no difference. I suspect the heater control valve sticks open, or maybe a control module gone skitzo, but need input on how to isolate the problem. Should I flush the cooling system first? Thanks in advance! Love this site!

[rjirvine]

the original door blend actuator is sticking when it heats up from the hot air blowing by. It will work again when you shut it off and cools down after a minute or two.. The newer part is built with better tolerances. I had the same problem on my 2000.

[orange300]

the original door blend actuator is sticking when it heats up from the hot air blowing by. It will work again when you shut it off and cools down after a minute or two.. The newer part is built with better tolerances. I had the same problem on my 2000.

 

 

Thanks! That makes sense. Is it difficult to replace? I'll research it also.

[rjirvine]

try this:

 

http://www.gm-trucks.com/forums/index.php?showtopic=98574

 

it's up to the right of your foot when its on the gas pedal. Easy to replace. I'd plug it in to make sure its in the proper position before mounting. Also, while you've got the cover off, go ahead and replace the cabin air filter (there are two pieces).