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AC Knob Issue- Real Teaser!!

SC_Hummer_Guy

Mr. Sexy Sugar Britches
Messages
264
Location
North Charleston, SC; Angel Fire, NM
So I have a really odd issue going on hopefully you guys can help. So I live in SC where it's always hot, but now that winter is here I don't need my AC on full blast. There in lies the issue:

If I have the AC button on or off doesn't matter, and it all the way over to the left (Cold) it works great. Freezes me out! However, as soon as I click it over once to the right, it blows straight heat as if I had it cranked all the way over the other way! WTF is going on!?!?!

Any help would be great!

PS: why the hell is my name pink on here, did you do that crap Dan????
 

f5moab

Mr. Beretta
Messages
1,986
Location
Hiding in a potato patch in Idaho
I'm going to suggest you check the battery cables to make sure they are tight. I would also recommend a recalibration of the actuators:
Turn ON the ignition with the engine OFF.
Turn the Temperature dial all the way to the right.
Turn the blower control dial all the way to the right.
Turn the mode position dial all the way to the left.
Simultaneously press and hold the A/C and Defrost buttons until the LED's start to flash.
Once the LED's stop flashing, calibration is complete.

I also believe Alrock has the same or similar problem.
 

SC_Hummer_Guy

Mr. Sexy Sugar Britches
Messages
264
Location
North Charleston, SC; Angel Fire, NM
I'm going to suggest you check the battery cables to make sure they are tight. I would also recommend a recalibration of the actuators:
Turn ON the ignition with the engine OFF.
Turn the Temperature dial all the way to the right.
Turn the blower control dial all the way to the right.
Turn the mode position dial all the way to the left.
Simultaneously press and hold the A/C and Defrost buttons until the LED's start to flash.
Once the LED's stop flashing, calibration is complete.

I also believe Alrock has the same or similar problem.


Thanks F5 I swear your a Hummer genius! Can I just pay you like a couple 100K to come overhaul my truck haha
 

f5moab

Mr. Beretta
Messages
1,986
Location
Hiding in a potato patch in Idaho
For a couple hundred K I would gladly do it. But hope the fix works, if not might require an actuator or two or a new control head. And, I'm not a hummer genius, just try and help when I can.

If you need any procedures for actuators let me know.

If you have anyone around with a H3, you can swap control heads and see if it still acts up. If, not it would be the control head.

It's an easy swap to try.
 

cbetts

NERD!!!
Messages
3,182
Location
Rancho Palos Verdes, CA
I have this issue every time I have disconnected the control to remove the center dash piece. I think F5 gave me that procedure before but I forgot about it. Glad you are back to functional.
 

alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
I should try the calibration again as my HVAC is doing the same thing - and I've replaced BOTH actuators AND the control unit. There just ain't that much else to replace so I'm a bit frustrated.
 

06 H3

a.k.a. "The Jackal"
Messages
9,350
Location
Meridian, ID
Im gonna try this later. Sc hummer guy asked me what to do on Facebook and found out I have the same issue. F5 you know your stuff. Don't leave once you get a jeep we need ur expertise!

Sent from my DROIDX using Tapatalk
 

alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
Mine's back to doing it again. It was working for a few months and has gone back to full hot when one click off cold. It has repaired itself before too. I did the calibration and it didn't fix it.

One thing that did happen is that the battery fully died on Saturday and had to be recharged.
 
D

Dennis

Guest
I'm going to suggest you check the battery cables to make sure they are tight. I would also recommend a recalibration of the actuators:
Turn ON the ignition with the engine OFF.
Turn the Temperature dial all the way to the right.
Turn the blower control dial all the way to the right.
Turn the mode position dial all the way to the left.
Simultaneously press and hold the A/C and Defrost buttons until the LED's start to flash.
Once the LED's stop flashing, calibration is complete.


.
This is going in my "How To" file in my Maintenance book on the H3..Excellent stuff..

Thanks F5
 

humbleag

Member
Messages
22
Location
College Station Texas
Mine's back to doing it again. It was working for a few months and has gone back to full hot when one click off cold. It has repaired itself before too. I did the calibration and it didn't fix it.

I had the same problem with my '09 (well, the second '09 since I had two). Took it to the dealer and they put a resistor in the control circuit, worked fine after that. Don't have that truck anymore, so I can't look to see what size/type resistor, but it seemed to be a common thing.
 
D

Dennis

Guest
Thanks as always F5! Anybody have any idea why when I have the system shut off air still comes through the vents? Would this correct that?
I don't think there is an total OFF position per se...If you have the fan OFF and the System button pushed for Re-circulate..then you shouldn't get any air through the vents...If Re-circlate is not ON, you will get outside ram air from just the truck going down the road....At least this is how mine works.
 
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