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Discussion Starter · #1 ·
I inherited a 2000 Silverado 5.3 liter extended cab 4WD with about 100k miles on it and have been trying to refurbish it a bit.

The temperature damper actuator had failed (the position feedback potentiometer wiper had become intermittent and my cabin was permanently hot), so I replaced the actuator. Now I've got some control authority over the cabin temperature, but it's still not possible to be comfortable most of the time.

With the HVAC control set to AC off and min temperature, I get what feels like unconditioned exterior air. Good. As soon as I move the temperature knob up by one detent, I get too-warm air. If I set it to max temperature I get very hot air. If it's 30-60 F outdoors, I can't set the knob to something that keeps the cabin comfortable. I'm either too cold, too warm, or broiling. There is no mid-range.

Thinking that maybe the climate control board had a bad temperature potentiometer, I desoldered it and replaced it with another potentiometer. No change in behavior. And I verified that the original pot was working fine. As far as I can tell, the temperature door actuator is moving quite a lot for the first detent, though it seems pretty linear thereafter.

What could be causing this strange behavior?
 

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YOUR 2000
I inherited a 2000 Silverado 5.3 liter extended cab 4WD with about 100k miles on it and have been trying to refurbish it a bit.

The temperature damper actuator had failed (the position feedback potentiometer wiper had become intermittent and my cabin was permanently hot), so I replaced the actuator. Now I've got some control authority over the cabin temperature, but it's still not possible to be comfortable most of the time.

With the HVAC control set to AC off and min temperature, I get what feels like unconditioned exterior air. Good. As soon as I move the temperature knob up by one detent, I get too-warm air. If I set it to max temperature I get very hot air. If it's 30-60 F outdoors, I can't set the knob to something that keeps the cabin comfortable. I'm either too cold, too warm, or broiling. There is no mid-range.

Thinking that maybe the climate control board had a bad temperature potentiometer, I desoldered it and replaced it with another potentiometer. No change in behavior. And I verified that the original pot was working fine. As far as I can tell, the temperature door actuator is moving quite a lot for the first detent, though it seems pretty linear thereafter.

What could be causing this strange behavior?
your 2000 Silverado is the HVAC control semiconductors ... my 2000 HVAC manual was working , not on my semiconductors of the truck ...the HVAC automated was over 10-15 yrs GM was not working .. look up the internet control board or do the troubleshooting ..GM did not post the schematic no control board ..
 

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2000 Silverado Z71 4x4 5.3L 480k+ miles w/ GM rebuilt motor and trans
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2,346 Posts
I inherited a 2000 Silverado 5.3 liter extended cab 4WD with about 100k miles on it and have been trying to refurbish it a bit.

The temperature damper actuator had failed (the position feedback potentiometer wiper had become intermittent and my cabin was permanently hot), so I replaced the actuator. Now I've got some control authority over the cabin temperature, but it's still not possible to be comfortable most of the time.

With the HVAC control set to AC off and min temperature, I get what feels like unconditioned exterior air. Good. As soon as I move the temperature knob up by one detent, I get too-warm air. If I set it to max temperature I get very hot air. If it's 30-60 F outdoors, I can't set the knob to something that keeps the cabin comfortable. I'm either too cold, too warm, or broiling. There is no mid-range.

Thinking that maybe the climate control board had a bad temperature potentiometer, I desoldered it and replaced it with another potentiometer. No change in behavior. And I verified that the original pot was working fine. As far as I can tell, the temperature door actuator is moving quite a lot for the first detent, though it seems pretty linear thereafter.

What could be causing this strange behavior?
I've had my truck since 2011. It has ALWAYS done this. I also replaced the blend door actuator (complete failure) and no change. I've been curious if the blend door is supposed to have the same foam shroud the AC vents have around them. With that gone, the slight opening in the blend door would be mostly open, depending on the geometry of the opening.
 

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2000 Silverado Z71 4x4 5.3L 480k+ miles w/ GM rebuilt motor and trans
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I've only ever turned my blend door controller to the first detent above max cool when running the heater. I use MAX heat with the windows open to defrost the front glass, but otherwise, it's on max MAX cold.
 

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Discussion Starter · #5 ·
Alright, I ordered a replacement aftermarket climate control module; we'll see if that does anything different. I don't have my hopes up, however. I wonder if I can put an Arduino or something similar to intercept the signal and remap it.
 

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2007 GMC Sierra Classic 2 wh drive
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I inherited a 2000 Silverado 5.3 liter extended cab 4WD with about 100k miles on it and have been trying to refurbish it a bit.

The temperature damper actuator had failed (the position feedback potentiometer wiper had become intermittent and my cabin was permanently hot), so I replaced the actuator. Now I've got some control authority over the cabin temperature, but it's still not possible to be comfortable most of the time.

With the HVAC control set to AC off and min temperature, I get what feels like unconditioned exterior air. Good. As soon as I move the temperature knob up by one detent, I get too-warm air. If I set it to max temperature I get very hot air. If it's 30-60 F outdoors, I can't set the knob to something that keeps the cabin comfortable. I'm either too cold, too warm, or broiling. There is no mid-range.

Thinking that maybe the climate control board had a bad temperature potentiometer, I desoldered it and replaced it with another potentiometer. No change in behavior. And I verified that the original pot was working fine. As far as I can tell, the temperature door actuator is moving quite a lot for the first detent, though it seems pretty linear thereafter.

What could be causing this strange behavior?
Why not try recalibrating air blend door actuators.With key on and engine off place temperature control to all the way hot leave it there for 1 minute, then move all the way to cold for I minute. This resets the travel limits on the actuators
I inherited a 2000 Silverado 5.3 liter extended cab 4WD with about 100k miles on it and have been trying to refurbish it a bit.

The temperature damper actuator had failed (the position feedback potentiometer wiper had become intermittent and my cabin was permanently hot), so I replaced the actuator. Now I've got some control authority over the cabin temperature, but it's still not possible to be comfortable most of the time.

With the HVAC control set to AC off and min temperature, I get what feels like unconditioned exterior air. Good. As soon as I move the temperature knob up by one detent, I get too-warm air. If I set it to max temperature I get very hot air. If it's 30-60 F outdoors, I can't set the knob to something that keeps the cabin comfortable. I'm either too cold, too warm, or broiling. There is no mid-range.

Thinking that maybe the climate control board had a bad temperature potentiometer, I desoldered it and replaced it with another potentiometer. No change in behavior. And I verified that the original pot was working fine. As far as I can tell, the temperature door actuator is moving quite a lot for the first detent, though it seems pretty linear thereafter.

What could be causing this strange behavior?
Try recalibrating the actuator limits. Turn key on engine , move temp. all the to hot and let it stay that way for at least 60 seconds. Then move temp. all the way to cold and let it sit at least another 60 seconds.
Turn key off DO NOT START. After that then start up. You may have to do this multiple times. This procedure sets the limits hot and cold. Even a new actuator needs to be calibrated.
 
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