problem with ac climate control need some help..
 

search but no luck. when climate control is all the way on cold blows cold air but only one click down and blows hot air i try the ac calibration and still the same, anybody has any clue what it could be any input would be apreciated thanks.

forgot to say: hummer h3 2006

Check resistor
 

Is it possible that the resistor has partially blown? My AC cut out this summer and to fix it I need a new relay and resistor. Both were easily installed within two hours with no help needed.

i will check those parts but te ac and heat are working but when i try to lower the temp from the cooldest to hot just clicking one towards the heat start blowing really hot air .

Same problem
 

I have the same issue. It's happen in the past as well. Last time I fixed it, or so I thought, I had a vacuum line unplugged. this could have been a total coincidence. Also, this problem started after I disconnected battery. The recalibration trick doesn't work for me.

Any luck???? :confused:

when you turn it down and it starts blowing warm air is the ac pump clutch disengaging? if it is still running it sounds like it'd be something under the dash or the switch opening and closing the duct work improperly

What occurs is, I have the AC control on coldest setting. Once I move it one click warmer, it stays cold for about 10 seconds, then starts blowing full heat. I believe its a problem with the blend door actuator. This seems to be a common occurrence whenever the battery is disconnected and reconnected.

Thats exactly what hapening with mine and i disconnect my battery too try calibration and still the same ......m#$#% F$%$%)*annoying but i will find what it is wrong and posted so every one can fix it or if somone find the problem please share with us thanks... lol

Be sure to post your findings!

I will wont be anytime soon cause ill be on vacation when come back I will fix it and post whatever was wrong.

Any luck finding a fix?

Not yet im in vegas but ill find the problem and posted I read a lot of people have same problem but no fix ill read some where changing controls for an specific part number or about reflashing computer hoping is the controls because goin to dealer for re flash probably they goin to F»*+$€#$$$$$$...

Common problem, there should be a thread somewhere about a fix. Mine was in warranty when it happened, dealer replaced a resistor in the switch assembly, that took care of it. I believe there may be a TSB about it as well.

Ill search all over the internet and nothing. Most of the fix are about blowers resirtors and conectors but not a fix on climate control I dont know if resistor or relay of blower would afect climate control but ill find out cause its annoying not to be able to adjust it sux...

I just bought a '07 and realized that I have the same issue too. I just figured its working well since it was blowing super cold but one click off max and it turn to HOT. Has any one figured out what the fix is? I did try to recalibrate with the steps but it does not fix the issue.

Not yet just came back ill start checking was causing the problem maybe this weekend.

I still haven't found the issue either

I can't find the previous thread where I posted the exact text from the service work at my dealer (put resistor in switch line, from reading the service bulletin below it appears that changes the feedback voltage for the actuators). Looks like they changed it to replace the entire assembly.



#PIT4704A: HVAC Temperature Goes Full Hot When One Click Off Full Cold - keywords A/C AC actuator air compressor door heat heater mode - (Feb 18, 2010)


Subject:

HVAC Temperature Goes Full Hot When One Click Off Full Cold


Models:

2006-2008 Hummer H3

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This PI was superseded to update the Recommendation/Instructions. Please discard PIT4704.
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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:


Some customers may complain that the temperature will go to full hot when they turn the temperature one click off of full cold. The control head is defaulting to Emergency Mode (this provides HOT air for safety reasons which would be available to clear the windshield in Defrost mode). This will happen if the feedback voltage for the air temperature actuators are out of range.

Recommendation/Instructions:


Replace the HVAC control head with part number 25920831.

Is the problem of the temperature control related to the resistor that is mentioned with the blower fan failure? Is it the same resistor mentioned in other posts? Or is it another resistor that is associated with only the temperature control? Please let me know as I just completed the correction for the fan control failure and now I have the issue of only 1 position for A/C and then it automatically changes to very hot on the next position up from full left position of the temp control. Anyone have any info?

I did the repair for the fan control, resistor/harness connection correction, but now have the issue of only 1 position for A/C. Checked all the positions for defrost, floor, vents, and combinations of the any one of the positions work fine however the temperature seems to default to a very hot with no adjustments past the two position from full left for cold. Does anyone know the proper procedure to perform for a reset.I did pull the fuses n relays to check before I started the above repair so I assume that is why I should try a reset/recalibration. Thanks!

Turn climate knob all the way to right, fan knob all the way to right, setting knob to left. Hold the climate button and control button down until they stop blinking.

We all have the same issue as you do. This reset did not fix my issue. Let me know if you find a fix. Thanks

Phase did you replace the temp. Control that Humbie posted with the service bulletin? Or did you just change out the blower motor resistor?

Im back but im so busy at the moment I will post when I get this fix, I saw tha part replacement I think im goin to order after I check mi resistor and connector I really think is goin to be the controls.

This makes me thinks its a computer issue. We all have the problem after power was disconnected. I checked my actuators today and they seem to be working. This problem has happened to me before, then fixed itself. So it doesn't seem to be an issue of something "breaking". I see this issue all over the internet, but no fix. ugh

I tried the reset several times but my led lights never would stop blinking. I assume there is something else going on that does not allow for the reset to happen. I did read though that the reset is used primarily when the whole control panel is replaced. Still researching about the 60 to 68 ohm inline resistor to bring back the reference voltage into range. I am doubting anyone should do this as it doesn't make any sense as the voltage to the swith is only 5 volts. Unless a circuit in the control panel has malfunctioned then I not sure adding a resistance would be the best plan. Kind of the same thinking on the fix for the burnt fan connector, it really doesn't explain why is it getting hot and expanding the spad connector inside the socket. No I didn't replace the temp control or any of the control module. If anyone has any more info please post. Thanks to all, seems to be a unsolved common problem on both of these issues.

*****i promise i will post when i get this fix, and is fix. the problem is controlers for sure i order the controlers and replace those myself so im 100% sure thats the problem the ones i have in my hummer are made in portugal and the ones i replace are made in mexico just for reference they have different part number good luck to every one fixing yours .

That's good news. Let us know if it stays working. Did you diconnect battery when installing? I've heard of stories people buying new control units then problem reoccurring a month later. Hopefully this works!

Fix to your problem
 

I remember the fix from a few years ago but the info is gone now, and I had a truck this morning with the same issue. I actually found the fix on a forum for 06 pontiac solstice. The light blue with black stipe wire, terminal f circuit 1688, on the driver side of the hvac control head needs a 60 to 68 ohm 1/2 watt resistor installed inline. it does something with keeping the voltages in spec. The new part #25920831 is suppose to also take care of this, older part # control heads such as 25814719 will not. Good luck, jason.

No I didnt disconnect battery, and yes I hope stays working, if not ill post.

I've heard of the resistor problem for the AC blower, but not for the temperature control issue. Is this a resistor that can be added for the temperature control rather than buying a new control unit?

Thanks for your help!

sorry for delay, just got back from vacation. the resistor goes in behind your old control head. you can get the resistors at radio shack. i have repaired 2 trucks in this manner.

Everything still working good?

Yes still working. I even disconnect the battery to see if is goin to quit working. Still working perfect.

Hey guys, I had the same problem and the dealer found the A/C .5 lbs low on feon which put it into emergency mode. The found the expansion valve was leaking, so they replaced it, recharged and the controls work fine again! Hope this helps someone else.

Your post of this is the first time I saw the resistor fix. I guess I never saw or was not interested whenever it was first posted.
I would like to thank you for posting it recently. It seems to be happening more often to more people. It happened to me and I did the fix.
Since I see people asking about it I thought I would post how I did it to help those needing more info. It's great to have people with a common interest getting together to fix things.

The procedure here is the HUNNER method of installing it. Proceed at your own risk.

• I did not disconnect the battery as I wanted to confirm this resistor fixed it instead of by some fluke disconnecting the battery did.
• Set the parking brake. Turn the key on.
• It helps to shift to Low. However leaving the key on will drive you nuts so after removing the dash piece I put it back in park.
• Disconnecting the battery would of course shut the dinger bell off. So I would recommend that and you can leave it in low to have more room, now that we know this did fix it. (fingers crossed)
• First you have to do the stick your fingers in the DC sockets and pull up and out.
• I cut me a piece of cardboard for a work surface in case solder dropped.
• I disconnected the plug from the back of the switch to get more room to work
• Find the light blue wire with black stripe. I peeled back the high quality gooey sticky black electrical tape GM chose to use far enough to expose the wire back into the loom so I could slide on some shrink wrap long enough to cover the splice.
• Call me old school, I'm old and went to school, but just as in my battery thread I make a physical connection first then solder.
• I used some forceps for a heat sink.
• I used a Radio Shack 68 ohm 1/2 watt resistor. They come 5 to a pack for $1.30 or $.26 a piece.
• If you don't know, use a low wattage iron so as not to fry the insulation on each end. Heat the wire until it pulls some solder as you feed it.
• Use some fine solder, Radio Shack still has that!
• Grabbed a short piece of shrink wrap I keep around. After the solder area cools slide the shrink wrap you remembered to slide on BEFORE you soldered over the entire splice. Use a heat gun carefully to shrink the wrap and secure and insulate your splice. I did not re-tape it at this time as I wanted to test it first. I will use a high grade of black electrical tape or some loom.

Now in transitional fall weather you can adjust the air temp but leave on the air conditioning to freshen your cabin temp and humidity!
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Thanks for posting the resistor repair. I did the repair this past Sunday and it worked out perfectly. The photos made it easy.

fix worked for me as well.

Worked
 

The resistor trick worked for me! I'm sure this is just a bypass for the air conditioning's emergency mode.

the resistor fix trick seems worth my time. My climate control does something similar on my 06 h3, it is actually stuck on cold a/c setting. when I turn the knob nothing happens. no warm air, no hot air., just cold a/c in any mode or temp setting. I have tried calibrated to no prevail. a local shop looked at it and said the actuators aren't getting voltage, they say I shouls replace the whole temp control head for $400. good grief. I think I will try the resistor fix first. any ideas? DQ

should I try the resistor fix also?
 

the resistor fix trick seems worth my time. My climate control does something similar on my 06 h3, it is actually stuck on cold a/c setting. when I turn the knob nothing happens. no warm air, no hot air., just cold a/c in any mode or temp setting. I have tried calibrated to no prevail. a local shop looked at it and said the actuators aren't getting voltage, they say I shouls replace the whole temp control head for $400. good grief. I think I will try the resistor fix first. any ideas? DQ