Having problems with your 2003 GMC Sierra 2500HD ?

My climate control starts blowing hot air while a/c is on

\015 When I have the interior temp. set to around 70 degrees and it's 95 degrees outside, the passanger side (only) starts to blow hot air regardless of where the temp. is set to. Sometimes shutting off the vehicle (which isn't an option when doing 65mph on the freeway) will work, but only temporarily, and sometimes turning the passanger temp control all the way to hot will result in a gradual cooling. Once the air starts to blow hot when dial is turned to warmest setting, if I turn the dial to the coolest setting, it will start to blow cool. Most of the time the cool air is only temporary, but once in a while it lasts for a while. \015\012I usually end up switching the dial from coolest to warmest, get a few minutes of cool air, then it starts to blow warm. Turn it to warmest and once cool air flows, turn it back to coolest. This is only temprary, and eventually I end up with full smoking hot air blowing from my passanger vents. I get frustrated, turn the climate control off, roll down the windows and sweat my tackle and berries off. PLEASE HELP ME! everytime I take it to the dealer it costs me a small fortune, and I'm desperate as my wife won't ride in it till I get it fixed and I hate driving her KIA.\015 Posted / edited by AnonymousUser on : 15-01-2018

Answers :

Make sure you have fully charged AC sytem first, if so Im sorry to tell you this but this is a difficult deal.you may not be able to correct this without taking it to a repair shop with gm scan tool. Reason being the actuators for the hvac that most likely are malfunctioning from either them or another component being bad , require recalibration.The other reason would be the body control module related.It would have to be scanned for U codes which can effect the hvac control.Sorry but thats what I know.
Repair Help & Product Troubleshooting for 2003 GMC Sierra 2500HD

Tips for a great answer:

- Provide details, support with references or personal experience .
- If you need clarification, ask it in the comment box .
- It's 100% free, no registration required.

Suggested Questions/Answers :

Climate control always blows extremely hot air no matter what setting is on digital control. When this first started in the summer, the air conditioning would work great then it would change to hot heat. Now, it blows hot heat all the time. No cool or warm air, only heat as if the setting is on 90 degrees. What are some areas I need to look at in order to solve this.


First thing. does the air compressor kick on ? ... 1994 Ford Thunderbird

I have a 1999 Cadillac Deville Concorse. The climate controls are all on the dash below the radio. The drivers side works perfectly (both hot and cold), but the passenger side works intermittently. If I turn the heat on, the passenger side blows cold air for some time...then suddenly starts blowing hot air after 5-15 minutes of randomly adjusting the controls. Was wondering if my control panel is bad (and if there's any way to test it), or if the actuating lever may be gummed up...is that possib


... 1999 Cadillac DeVille

My climate control starts blowing hot air while a/c is on


Make sure you have fully charged AC sytem first, if so Im sorry to tell you this but this is a difficult deal.you may not be able to correct this without taking it to a repair shop with gm scan tool. Reason being the actuators for the hvac that most ... 2003 GMC Sierra 2500HD

Air conditioner blows hot air after 30 seconds on drivers side, on start up. Passenger side works fine. Air blows out correct vents per setting on air conditioning. Replaced blend door actuator on drivers side. No change. 2004 gmc Yukon with dual climate control.


I have had this problem. I am not a mechanic...so to correct the issue temporarily, I simply turn off the car and restart. This has worked everytime for me. In extreme cases, I think you can also remove the AC fuse and start the car, which will als ... 2004 GMC Yukon

In my 04 gmc sierra (with electronic duel climate control). It takes a long time for it to start blowing heat and when it finnaly does blow hot air after about 10 min. It will go back to blowing cold air any ideas?


You have air in the coolant system, check the resevoir and radiator if you can. iy needs to be puged . remove the resevoir cap start the vehicle and let it warm up to operating tempeture. kepp check on the resevoir and fill as needed. if some comes o ... GMC Sierra 1500

1995 bonneville sse w electrical climate control. the temp display flashes after start up for 30 sec. and no hot air will blow. will blow heat intermitantly. totally random. just started now that's jetting cooler. figures.


... 1995 Pontiac Bonneville

I have a 2003 Buick Rendezvous. The drivers side blows hot air and the passenger side blows cold air. The car has that dual zone climate control. I have no clue where to start.


The actuator that 'blends' cold with hot is stuck in the cold position. There are a couple of options. Disconnect the battery, then drive the vehicle around without using the AC for 10 min, if the AC is defaulted to come on after a battery interuptio ... 2003 Buick Rendezvous

We are having couple of problems with the Automatic climate control. First it does't work when the car is very cold. It only blows air out the rear vent.( I understand that their is a delay, but long after the delay counts down it still does not work) We then turn off the automatic climate control, and the air will the start to blow out the front vents, but sometime it won't and we have to let the car idol for 20 minutes before the air will start to blow out the front(very sporadic). Secondly, t


The only way to accurately access this condition is with scanner and testing.\015\012\015\012You could have a AC relay that is stuck on. Its located under the hood. Just remove it for now and see if the heater issues change. Its located ... 2001 Dodge Grand Caravan

Climate control does not blow cool air. When I turn the temp down there is no change in air temp. It blows full hot air. Sometimes I can give the dash a smack with my hand and it will blow cool air, but that only works once in a while. I know the the system is charged. Should I change out the climate control?


You going to have to tear the dash apart (ac control panel) to see why your switch is not working. The control valve unit works on vacum systems and you need to find out where is leaking or the hoses is old and broke off. If your ac comp ... 1991 Buick LeSabre

When auto climate is engaged and temp control set to "Lo", it seems to work OK. When either of the temp control knobs are adjusted up in temperature, it starts to blow hot air on that side. I just got the car (not familiar with it yet) and manual does not help. Any ideas?


Have you tried setting the temp before activating the auto control.......i know that the saab's auto control shuts off when you manually adjust the temp, after manually adjusting the temp , you have to then engage the auto temp control..maybe its the ... Volvo S80

At a cold start it blows cold on drivers side, passenger side is always warm, after driving 10 to 15 minutes it blows hot. air bag light is also on, I understand this is probably the clock spring. Could this be related? I have dual climate control.


THE AIRBAG AND AC ISSUE ARE NOT RELATED, KNOW THIS FOR SURE I AM A FORD DEALER TECH AND SPECILIZE IN AC PROBLEMS. THE 1ST THING YOU NEED TO DO IS HAVE THE CLIMATE CONTROL HEAD IN THE DASH SELF TESTED, BUT BASED ON YOUR SYMPTOMS I SUSPECT IT AND AT ... Lincoln LS

Air conditioner problem in Nissan Extera: works fine sometimes then will only blow hot air at other times. internet search shows that Thermo Control Amplifier in or near evaporator core is common problem. Lots of unhappy people on internet due to misdiagnosis of this problem. Noticed yesterday that when very hot inside car, AC blowing hot air. Later after driving stopping a couple times, started working just fine. My understanding is that the thermo control amplifier will shut off the clutc


Check the resistor pack/board on the cabin fan ... 2005 Nissan Xterra

I can not get hot air to come through the vents on the left side (passenger side)but when i change the direction controls on the climate control panel the air changes direction so we can assume the doors in the system are working.Heat blows freely on the right.When recycle air is on, cold air still comes through the right.The CT did put a ligt on the AC when turned to Lo and on recycle air.When on Hi it put recycle on blows hot air every where to achive temperature it does not do that now.I rang


You need to check under dash to make sure plastic heat pipe is in place to that vent ... Jeep Grand Cherokee

Lack of power, hesitation, climate control blowing hot air


... 2006 Lincoln Mark LT

Climate control my climate control is stuck and it will only blow out really hot air. The defrost is running all the time hot air. I am on vacation in an already hot place. What do I do?


Try putting the selector in a desired position with the key on then turn off the key and disconnect the battery for 10min. ... 2002 Ford Taurus

2005 tahoe will not blow air in the front when at idle or setting still. Setting still you can run 2000 rpm still will not blow. When you start moving about 20 mph it will blow but only 1 speed (about mid speed) no matter what you set the controls on. Slow down to stop and it stops blowing. The temp control works so if you set it on 60 degrees it blows cold on 75 it is warmer. If you turn teh heat on it blows hot but only when moving and you can not control the fan speed. Rear air works fi


... 2005 Chevrolet Silverado

2002 Jetta A/C is not working.. It's blowing hot air (not warm, not air that's just 'not cold', but air so hot you can't keep your hand there long)... I had a problem with the radiator fans, but replaced them and they work fine, also just replaced a fuse (#5, which controls a/c, climate control, cruise control, that was missing), and it fixed my cruise control problem, but don't believe it fixed the A/C problem...


Well i have the same problem i did some test but in my case it loks like the magneric clouch is not working . i put direct power to engage the compresor and nothig. there is a module on the left side of the engine just under the bat it has 2 conector ... 2002 Volkswagen Jetta TDI

Hi I have a 2000 Ford Expedition. I had front and rear heater core replaced by a mechanic. Front heater works great but now the rear heater blows warm not hot air. Took it back and the mechanic flushed the system but rear heater still blowing warm air. Mechanic insist its the climate control switch but it was blowing hot air before the rear new heater core was installed..... Does anybody knows what it could be? Please help


Is the correct type of heater core that use for rear heater?Check fan fix its correct side,or wiring change or return water line is blocked. ... 2000 Ford Expedition

2000 Mercury Grand Marquis will only blow hot air when ac is on. The ac system does work lines get cold but will not blow nothing but hot air. Has automatic climate control system. Will direct air from vents to floor and defrost like it should when you change the settings.


YOU MAY HAVE AND O RING LEAK, IF YOU HAVE YOUR AC ON AND HEAT BLOWS .ARE IT COULD BE YOUR AIR DOOR STAYING OPEN BECAUSE IT IS STUCK IT IS CALLED YOUR CONTROL PANEL SENCER OR MOGULATOR THAT WENT OUT I HAD THE SAME PROBLEM THANK GOD IM A MACHANIC ... 2000 Mercury Grand Marquis

I have a 2002 Jeep Grand Cherokee Limited with the automatic climate control option. Within the last few weeks, I have noticed cold air seeping under the passenger side dashboard, near the blower mechanism. It seems that the faster you drive, the more air comes in. I checked the heater operation and found that it does blow hot air out of the floor vent at the same time, so the climate control is operating correctly. Could there be a poor seal around the blower assembly. Any help would be appreci


It could be a poor seal but I've never seen it. What you could have is\015\012a fresh air door not closing properly. Fresh air door/recirculation\015\012same thing. ... 2002 Jeep Grand Cherokee

I have a 2001 BMW 330I. When I use the automatic function of the climate control it blow hot and cold air. The AC button is on and the automatic button is selected and the thumbwheel of the center air vent is all the way to the blue. Temperature is 59F but blowing hot and cold air. Please help so I can get this fix


... 2001 BMW 330

Rear heater blows only cold air no matter what the settings are at. Front heat works well. I have tried using both the front and rear controls to set the temperature, but the rear vents will only blow warm air at best. The air starts out as cold as the outside air even when the engine is warm and the front is blowing hot air. It takes several minutes for the air to get slightly warm.


If this is equipped with a rear heater core it is probably plugged up and needs to be disassembled and cleaned out ... Chevrolet TrailBlazer EXT

A/C started blowing hot, was working this morning. Have replaced idle air control valve, a/c switch, and full recharge(I leaked it all out while changing the switch, and it would not take a charge, so I had a garage recharge, and replace the switch again, as I had threaded it during install) My next repair will likely be the clutch plate, but I am curious why it started blowing hot constantly all of a sudden. I have owned it for 3 weeks, and the original problem was that the a/c would work fine


... 1997 Ford F150 Regular Cab

2003 GMC SIERRA DIGITAL DUAL ZONE CLIMATE CONTROL WITH HEAT SETTING AT HIGHEST POINT WHICH IS 90 BLOWS HOT AIR, SET IT A 89 OR LOWER AND A/C TURNS ON AND BLOWS AIR AT 50, NOTICED AFTER CONTROL IN THE DASH WAS UNPLUGGED TO REMOVE RADIO ANY HELP


... GMC Sierra 1500HD

Blowing outside air through the vents all of sudden hot air starts blowing. then when the A/C is on, same thing happens. I can hear a clicking as if the thermostat control is going from cold to hot.


Sound like blend door problem ... 2001 Dodge Ram 1500 Truck 2WD
  • Start your question with What, Why, How, When, etc. and end with a "?"
  • Be clear and specific
  • Use proper spelling and grammar
all rights reserved to the respective owners || www.carrestorationshop.com || Terms of Use || Contact || Privacy Policy
Load time: 3.0870 seconds