Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Did you get a great deal? Let us know in the Values & Prices Paid section!
Meet your fellow owners in our Owners Clubs

Chevy Silverado and GMC Sierra Climate Control



  • dwhite456dwhite456 Posts: 5
    read through all the posts...all of them.

    Have problem with suburban blowing hot through all vents. Have front and rear heat/AC controls. Single controls for right and left.
    2 summers ago AC started blowing warm in front but still a bit cold in back. Ran some new refrigerant in it. It wasnt really low but still put some in and the level remained in the normal zone. Air blew cold again for a while.

    Last summer air was blowing hot again, now this time it was in both front and back. bought another can of refrigerant. Same deal...wasnt really low but put some more in. Air blew cold for about 2 weeks then stopped.

    Need help troubleshooting to root.
    What I know is that the compressor is spinning as I can see it turning when on. Cant really hear any clicking or anything indicating the system is trying to cool. What else can I check to try and narrow the problem down? i can leave it running with ac set to on and I dont see any condensation on any of the metal lines under the hood. I also checked all the fuses and relay and didnt see any problems. Did the pull ac fuse under hood reset thing and nothing came from that.

  • obyoneobyone Posts: 8,054
    You have a leak resulting in refrigerant loss. You can add dye which comes with some of the refrigerant at most parts stores or you can save yourself the headache and take it to a shop.
  • dwhite456dwhite456 Posts: 5
    edited June 2011
    I dont think I have a leak as each time I shot some more refrigerant in there it was in the normal zone. I just shot enough to take it to the top of the normal zone.

    Today I check the actuator that is over the hump on the passenger side. Everything checked out and the motor was moving and it was operational.

    I appreciate you replying
  • obyoneobyone Posts: 8,054
    The a/c system will run warm with low refrigerant and cool when more is added definitely has a leak. Might be a slooooow leak but still a leak. Another indication of low refrigerant is the constant recycling of the compressor.

    I had a '02 Denali and though I added the dye, I couldn't find the leak. That is until I checked behind the passenger rear tire and found what appeared to be a plugged drain hose. Unclogged the hose and a ton of water and dye spilled out. Apparently, the clogged hose cause the rear evaporator to fail and leak.

    Course another possibility could be in the temperature control. Not sure if you have auto or manual. Still comes back to the a/c working when more refrigerant is added.
  • dwhite456dwhite456 Posts: 5
    edited June 2011
    thanks, I will check for a leak and maybe add the refrigerant that has the dye in it.

    I have manual AC. Is the temperature control the actual circuit board behind the manual dials?

    I got down and looked behind the back rear passenger tire. I saw what looked to be like a black rubber thing. Didnt know if that was the nipple that people are talking about?
  • obyoneobyone Posts: 8,054
    The black drain tube in back of the passenger rear tire looks like a rubber piece with a 1/2" slice in it. A flat head screw driver would be perfect to open it a little and see if you have water accumulating in there. Careful not to be directly below it when prying.

    I'm assuming this is the controller that you're referring to. Yes it does have a board in it.


    How long is the time period between topping off and the unit blowing warm air?
  • dwhite456dwhite456 Posts: 5
    Last summer when I shot it with some more refrigerant it blew cold for about 2 weeks and then it went back to blowing air temperature again.

    Yes, that is the manual controller that I have. You suggested maybe it was a temperature control problem. Is replacing the controls or the circuit board the solution for a temperature control problem?
  • obyoneobyone Posts: 8,054
    Is replacing the controls or the circuit board the solution for a temperature control problem?

    Of the controllers that I've seen fail, about 90% was the fan speed control switch and the other 10% was the directional control. Never seen a failure of the temperature control but it is possible.

    While there is no "standard" time between refills, two weeks would be a reasonable amount of time for a slow leak. The last time I had a leak it was three months between refills so I didn't bother to fix and traded the truck instead. When I had the leak with the Denali's rear evaporator, the hole was so large that trying to top off with R134a wasn't an option as it would escape as fast as it went in.
  • 5five5five Posts: 2
    I have the above vehicle with the digital dual climate control system.

    I am experiencing problems with the driver's side blowing hot air while the pass. side remains cool at various times.

    I have checked other forums and have found ideas but no answers. When I pull all my HVAC fuses, the problem corrects for a short period of time but when shut off and restarted returns.

    I have had the dealership reflash the HVAC computer and I am still experiencing the same problems. In fact they told me that all of the "old" model year problems have been fixed.

    I know it can't be faulty blend door actuators or it wouldn't go cold at all it would be locked in position.

    I know it has to be some sort of computer/electrical issue since pulling fuses fixes it temporary 75% of the time.

    Any suggestions? I am out of warranty..... :(
  • gmcustsvcgmcustsvc Posts: 4,252
    I apologize for your frustrations. Has the dealer tried to envolve Technical Assistance? I look forward to your response.
    GM Customer Service
  • dwhite456dwhite456 Posts: 5
    Put some more refrigerant in it and it is still the same. One thing I did notice.....The AC pump was spinning but it didnt seem like it was cycling. After putting some refrigerant in it at least started cycling albeit did sound a bit rough or strained.
    Any other ideas or suggestions where to troubleshoot?
  • obyoneobyone Posts: 8,054
    If the compressor didn't cycle until you added the refrigerant it is safe to assume the level was really low. By adding the refrigerant it started to cycle meaning that it had enough 134 to start cycling. It would usually be a fast cycle until you reach around 1.75 pounds of refrigerant.

    Were you able to add the dye?
  • codbrwncodbrwn Posts: 1
    I saw your post and have the same problem, have you found an answer yet? Thanks
  • i changed the resistor located on the blower motor and that was it!
  • dasani3dasani3 Posts: 2
    hey there...there should be two fuse panels...when you are sitting in your drivers seat there is one on the left side of the dash by your leg... you will need the drivers door open to see this... pull the panel off and on that panel there in i diagram what fuse is where and what its for... check that.. and then under your hood on the left side... this is a large square box pull the top off and do the same... i hope this info helps you
  • dasani3dasani3 Posts: 2
    i checked the plug in connection for power there was no power... all fuses and relay is fine... my ac is fully charged... is it the switch inside the next thing to look at.... how do you test the switch to see if it is working.... thanks
  • one2manyone2many Posts: 1
    I have a 2005 2500HD 4x4 and the blower fan cuts in and out when set on 3 if it cuts out i can tap on the duct n the passenger floor and it will return working. I was told that it was the blower resistor module and I went and bought a new one from autozone it costed around $60 to $65. I was also told it was a comon part to go out so when i took everything apart and got to it i noticed the plug on the end of my harnes that plugs into it was also burned so i taped up the burned wires to prevent it from burning any more and my conections looked good enough to work till i could find another plug so i put everything back together and it worked fine till i hit a bump then back to the way it was. So as for mine I believe the plug needs replaced to fix it and if yours is burned just a little and dont have a firm conection or is loose just a hair i would recomend starting there first its cheeper. As far as finding the plug i havent yet I was gunna try my local junkyards and probably pay $5 or $10 but they dont have anything that new so in waiting for them to get one but for now i keep something to reach and bump the duct when it goes out then its fine till the next bump. I know this Is long and drawn out but I hope it helps you
  • AC quit blowing on super-high, have been told this could be the recirc gate not closing. How do I test this and other gates, have been told that my truck might have three or four gates with motor actuators. Anybody have a diagram? I'm not very electrically inclined so please keep it simple as possible? Thank you in advance for your help!
  • there has been a recall on these vehicles ac not working. it is nearly impossible to find but i have uploaded the recall on my website. gm will replace for free.

    Models: 2003-2006 Chevrolet Avalanche, Suburban Tahoe

    2003-2007 Chevrolet Silverado

    2003-2006 GMC Yukon, Yukon XL

    2003-2007 GMC Sierra
  • gm did a recall on this. i put the link on my website cause gm makes it almost impossible to find.
  • I keep trying this link but am unable to get access. I have a 06 2500 HD the dealer replaced the part once then I had it replaced a second time at a cost of $400. plus.
  • The link is back on line. I create websites and had a demo site on line. Have a great day
  • Link is back online.
  • Great post and glad to see that recall. I DL'd the .pdf and posted it up on Diesel There might be a few of the 125,000 truck guys there that might find that interesting.

    Heres one for all. 2006 Sierra 2500 HD: in 'winter - Drivers side blows cold air - Pass side is normal at whatever temp setting is. Is this my mode actuator or a blend door actuator issue...or could it actually be the reflash that my truck might or might not have gotten.? Build date is Oct 05.

    To date I have simply (in winter time only), disconnected the batts for 5 min or so, turn key on and let system calibrate..worked all last year but a PITA when its -40 out.

  • My 2000 Silverado 1500 Climate Speed Control does not work on the first 3 speeds. It does work on speeds 4 and 5. Where or how do I trouble shoot the problem?
  • obyoneobyone Posts: 8,054
    You could buy one off of ebay.

    a/c controller

    Or remove yours and replace the diodes on the speed switch.
  • rayt2rayt2 Posts: 1,208
    Been a long time since I posted here but I still have my 2000 Silverado 2500 2wd excab shortbed.
    Here is the scenario: Parked truck for couple of days. Last night could not unlock door with key fob, OK use the key. No dome light, no start, no nothing evrything was dead.
    Hooked up battery charger, as soon as I powered up charger dome light came on and the defrost is running fullspeed with fan control set for "off", temp setting on midrange and source setting on "floor".
    I have no clue what happened or caused this.
    Any suggestions/help appreciated.

    Ray T
  • dhb4dhb4 Posts: 4
    I recently bought an 06 gmc sle and have been having trouble with the dual climate control. When I have the ac on or even just have the fan blowing with the temperature setting on cool. The driver side will start blowing very hot air and the passenger side vents are normal. When I turn the truck off and start it back up, it is fine for bit, and then it will do it again.
    Anyone have any ideas?
  • 5five5five Posts: 2
    No matter what setting, the driver's side would creep up and become hot.

    I tried every fix found on the internet and ended up going to the dealer who replaced the driver's side blend door actuator at the cost of about $400.

    It was fixed in late June and I haven't had a problem with it since.

    Good luck.
  • rayt2rayt2 Posts: 1,208

    Replaced the resister on fan motor housing and resolved the problem.
    $26 part at AutoZone in stock.

    Ray T
  • gmcustsvcgmcustsvc Posts: 4,252
    I would recommend taking it back to your dealer for the necessary information. If you have any questions or concerns, feel free to contact us directly. Good luck on your progress!
    Joey, GM Customer Service
  • I received the letter but have lost it. I think I am nearing the mileage cutoff for the repair. Can you send me the link or the pdf so I can print it up and set up an appt!! It is impossible to find anywhere else on the internet....
  • I can't get my heater to blow out hot air. In the past month I've changed the heater core, the thermostat and water pump due to separate issues but I still can't get it to blow out hot air from the vents. It does blow out cold air though. I also hear what sounds like bubbling/boiling water in the cab when I'm driving (stepping on the gas only). I really need to get this fixed before the really cold weather hits. What can I do???
  • obyoneobyone Posts: 8,054
    Sionce the heater system uses coolant to heat the air the most common cause of no heat is low coolant. When changing the thermostat, heater core, and water pump, the system needs to be topped off after the thermostat opens. If not you'll have low coolant.
  • redgeredge Posts: 1
    Have 2006 GMC 1500 doing same thing. One thru four works but # 5 does not. Received letter from GM last week (special Bullentin 10240) on manual temp control switch. Gm realizes theres a problem with the hvac system not working on certain blower settings and would repair this problem if taken to GMC dealership. Took my GMC to Macon Ga. dealership and was told #5 was not in the covered plan to repair. Dealership said it would cost 328.00 dollars to repair. Can anyone figure this out?
  • I'm glad that you posted, Redge.

    We would like to speak with the dealership to clarify a few things. Do you have an appointment already set up to have the repair done, or is your vehicle currently in at the dealership for repair? Please send us more information, including your name and contact information, the last 8 digits of your VIN and current mileage on your vehicle, and involved dealership. With this information, we will set up a case for you with Customer Assistance and will be following up for you with the dealership.

    Thank you in advance,
    GM Customer Service
  • Did you ever get this fixed and what was the solution? I have a chevy tahoe 2004 and I have had this exact same problem for a couple of years now. Thanks
  • Yes I did, after replacing 2 of the fan control modules I replaced the wiring harness at the fan. The stock harness overheats and melts, shorting out the contacts, bad design. Not hard to change, just have to pay attention, the replacement harness wiring isn't color coded. Can't remember if I bought the new harness on Rock Auto or off of ebay, but it was like $17.00. Good luck and Merry Christmas!
  • I have an 2006 1500, last week hot air stopped blowing out of the driver side vents and continues to work on the passenger side. It has sporatically come back a time or two but is gone again after the truck sits for a couple hours. Any Ideas whats wrong or how to fix it?
  • If you were to email us the last 8 digits of your VIN, we could check to see if there are any open recalls on the HVAC. When you do send this email, please describe your concern in it (as it can be difficult to link emails to posts at times, and we want to be best able to assist you).

    GM Customer Service
  • I forgot to mention that I did a radiator flush and I've kept checking the coolant levels and it is topped off. Still no heat coming out.
  • I'm having the same issue with my 2009 Sierra. Passenger side holds steady but the driver side keeps alternating between hot and cold on mine, even if I just have the vent on with no blower running. Sounds like the same issue you're having. Did you ever find out what it was because I'm stumped? Has to be a temp sensor somewhere that keeps triggering on and off. Do you have Dual Climate Control? Also, did the GM Rep ever get back to you?
  • Jwulf72,
    As your Sierra is a 2009, this may still be covered by the Bumper to Bumper warranty. We can let you know the specific parameters of your warranty if you were to send us an email with your name and the last 8 digits of your VIN.
    GM Customer Service
  • I think I found out on my 06 what it was, there is a connector just below the dash (easy to get to if you don't have the full center console) next to the driver side floor vent. It was loose like someone had stepped on it or pulled at it. I disconnected it while the truck was running, made sure it was clean and then firmly reconnected it. So far heat has worked on both sides for three weeks.
  • furrowjockyfurrowjocky north central MontanaPosts: 13
    on my 2011 Sierra 1500 crew, I have had heat distrubution problems since day one. Plugged off center vents to get more air flow on passenger side. Helped a little, seems like to much is going to defrost or vents are to small to passenger and drivers feet. Its 30 below zero here in northern Montana again, so it makes the problem very noticeable. 100 miles from dealer have'nt had time to take it in yet, purchaced in Jan now have 27000 mi on it. Unrelated problems, gravel has beat out rear back up sensors, passenger wiper leaves last three inches of windshield not cleared, and fabric on seats is impossible to get lint and hair off. Want my 06 back! I've owned GM for 35 years, currenty have 6, this has been most disappointing purchase ever.
  • Furrowjocky,
    I am sorry that your 2011 Sierra isn't currently satisfactory for you. I see that you may be looking at taking it in to the dealership for the heat distribution concerns you described - please keep us posted on how this goes. If you are not satisfied after the visit, we'd be happy to help follow-up with you and your dealer and continue seeking to resolve it.
    GM Customer Service
  • 2006 silverado..dual heat control...heater works but goes out when the truck idles for any length of time. then heats back up when the truck is back in gear heading down the road.
  • furrowjockyfurrowjocky north central MontanaPosts: 13
    Thanks for the reply. Took vehicle in to Bennett Motors on 1/25, no problem with heater was found, they're going to look into it further next appointment. The other reason for the last visit was evap system was plugged and haven't been able to fill with gas. They ordered in canister, but forgot to order solenoid, so my day off work and a 100 mile trip was wasted, they did apologize. As you probably know this is a chronic problem with pickups and suv's forever. I've spent a 1000 dollars on my two 06 pickups for new canisters and solenoids. Van Motors in Conrad Mt has been smart enough to reroute hose to front of vehicle, so it won't plug again. Bennett told me GM is coming out with a reroute kit sometime. The other problem with rear backup sensors being beat out by gravel could not be fixed under warranty. I guess pickups are not to be driven off highway! GM really needs some protection for these sensors. Oh and windshield wiper problem, they put on new wiper and discovered it does not touch last 2-3 inches of passenger side either, so they went out to their lot and looked at other 2011's and discovered none of them touch. I can't believe I'm the first one to notice this! I hope you take this note as constructive criticism, I do like the power, the handling, and looks of my 2011 Sierra 1500 crew, and have owned GM vehicles for 30 years and would hate to switch to the F word. I'll be in touch with how heat distribution problem goes, if you have any ideas, you can contact Sheryl Mcallister, service adviser, Bennett Motors, GT. Falls MT. Thanks
  • I look forward to further updates!
    GM Customer Service
Sign In or Register to comment.