Heater control module bad?

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Idaho45guy

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Sorry if it's been addressed somewhere else, but my laptop does not agree with this forum and it runs super slow, so searches are taking forever.

2005 Yukon with 96k miles. AC worked perfect last Fall. Got warmer and tried to use it a couple of weeks ago and no cold air. AC compressor not cycling on, so I bought a AC recharge kit. Showed no pressure when I initially hooked it up. Used the entire container and then the compressor started cycling but still no cold air.

Then, I noticed that even with the AC off, the fan doesn't blow until it's turned to the highest setting. Seems like the unit isn't responding.

I remember something similar happened last year when I disconnected the battery, the heater controls stopped working, so I had to disconnect the battery a couple of times and it seemed to reset itself.

That's not working this time.

So, to sum it up, I can have the fan control turned to 1 through 4 and no air is being blown through the vents. Turn it to 5 and it blows strong. I'm assuming this means that the control module is bad, correct?
 

Doubeleive

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Sorry if it's been addressed somewhere else, but my laptop does not agree with this forum and it runs super slow, so searches are taking forever.

2005 Yukon with 96k miles. AC worked perfect last Fall. Got warmer and tried to use it a couple of weeks ago and no cold air. AC compressor not cycling on, so I bought a AC recharge kit. Showed no pressure when I initially hooked it up. Used the entire container and then the compressor started cycling but still no cold air.

Then, I noticed that even with the AC off, the fan doesn't blow until it's turned to the highest setting. Seems like the unit isn't responding.

I remember something similar happened last year when I disconnected the battery, the heater controls stopped working, so I had to disconnect the battery a couple of times and it seemed to reset itself.

That's not working this time.

So, to sum it up, I can have the fan control turned to 1 through 4 and no air is being blown through the vents. Turn it to 5 and it blows strong. I'm assuming this means that the control module is bad, correct?
more likely the blower motor resistor has failed (it's very common) however that would not affect your compressor issue in any manner, all the blower motor does is blow air period. So for $30-40 you can do the blower resistor pretty easy yourself, and then if that does not resolve the air blowing on all settings you may have deeper issue's.
 
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Idaho45guy

Idaho45guy

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Did the reset and didn't help. Fan only blows on 5. Got another can and filled the system and compressor came on and cold air came out. Pressure needle went well into the green. Then it started dropping.

I have a leak somewhere.

Time to take it to a professional.
 

Rocket Man

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Did the reset and didn't help. Fan only blows on 5. Got another can and filled the system and compressor came on and cold air came out. Pressure needle went well into the green. Then it started dropping.

I have a leak somewhere.

Time to take it to a professional.
Damn that sucks. At least you tried. Mine had a bad Schraeder valve so I had to empty it to replace that.
 

Rocket Man

Mark
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reset/re calibration wont fix the blower motor problem
Nope, I just saw where he said something similar happened last year when he had disconnected the battery. I figured it was worth a try to get things working again, minus the fan control.
 

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