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Heat/AC system not working, help!

141K views 55 replies 33 participants last post by  Starla387 
#1 ·
I accidentally ran the battery down yeaterday and had to get a jump start. That afternoon I reset the clock, which was off by several hours. This morning I turned on the heater and it never got warm, so I decided to try the AC, never changed temp. the numbers change when you press the button, but the air comming out has just stayed the same temp, any ideas or suggestions? It worked fine before the battery thing.

Thanks!
 
#2 ·
I am going to base this off of a automatic heater control HVAC system since you say that the numbers change. I am also just guessing what year you have, but it should be the same across the board for gen 7. When you have time it will be helpful to others to have a signature which can be created in the user control panel.

The best thing I can think of starting with is turn the key off, disconnect the battery for a minute, and reconnect it again. Then, turn the key to the on position and let it sit for another minute, but don't mess with any of the HVAC controls. This should recalibrate all of the actuators in the system. After the minute cycle the key off and the back on and try it again.

If that doesn't work you will probably have to take it to the dealer to find out the codes in the system and get it diagnosed.
 
#6 ·
<snip>

The best thing I can think of starting with is turn the key off, disconnect the battery for a minute, and reconnect it again. Then, turn the key to the on position and let it sit for another minute, but don't mess with any of the HVAC controls. This should recalibrate all of the actuators in the system. After the minute cycle the key off and the back on and try it again.

If that doesn't work you will probably have to take it to the dealer to find out the codes in the system and get it diagnosed.
I remote started my 2011 LTZ after it was sitting about 1 1/2 hours outside in 45 degree weather and was quite impressed how warm it was when I got inside. I wasn't quite so impressed 5 minutes later when it was doing an imitation of toaster oven. Had to drive home with the windows open and the auto temp system shut down as best I could. It was simply poring out heat.

But, thanks to you guys, and trying to follow directions that chevyguy8893 provided, all appears good again. I appreciate all the wisdom here. I have to put a suit on in the morning (funeral) and hope I don't roast on the way.

More will be revealed, I guess, when the problem recurs or it doesn't.
 
#3 ·
^+1

Identifying your car will save us from assuming that it's a Gen7 just because you posted here.

And chevyguy8893 knows his stuff! Listening to him will get you a lot closer to solving your issues.
 
#5 ·
You won't have any issues with the radio by disconnecting the battery. You will just need to reset the clock afterwards.

DrivenDaily said:
And chevyguy8893 knows his stuff! Listening to him will get you a lot closer to solving your issues.
Thank you, I try my best to be as helpful as possible.
 
#10 ·
I know this post is a bit old, but if anyone else is looking for a solution to odd heat/AC issues, this solution worked perfectly for us! Ours would only do heat, only through front defroster. The fan speeds option worked. Now it is working perfectly. I was not looking forward to a road trip with cold feet and a hot face.
 
#12 ·
I am having an issue when I auto Start my car, none of my Heater controls work. I get no air out of the vents, no fan controls. . . absolutely nothing. It is 5 degrees. not nice when the heat doesn't work. Turned the car off and tried starting with the key instead of auto start. nothing. opened the hood, shut the hood...heat works? Any ideas?
 
#14 ·
Sounds like the motor or the wiring to it. A bump jars it enough to move a little and then the electric is able to keep it moving. Could also be a loose connection at the HU (head unit) but that is less likely. Check the fuses while you're at it.
 
#16 ·
Had this exact same problem on a 2011 Malibu (86000 miles, no previous problems of note.) Recently had to have it jump started and soon noticed that the climate control system would not respond to thermostat input: for several days it blew cold air only (no A/C, but just circulated outside ambient air.) Then it changed and, regardless of climate control settings, it blew max hot air. (The fan did respond to changes in setting.)

Bottom Line: I took your advance. Last night I disconnected the battery for about sixty seconds and then reconnected. Works fine now. Thanks!
 
#19 ·
Guys this is a normal occurrence with the gen 7 Malibu. If you look at posts I posted one last week "most annoying thing about 2010 Malibu" I'm sure GM and dealers know about it but again no fix. As I write this I'm trying to find a way the wire up a battery cutoff to inside of my car because every time this happens, I have to disconnect the battery. I'm tired of doing this on cold day and it seems that's the only way to get it to work. So I will figure out how to cut off battery from inside the car turn it back on a minute later put the key in power mode for another minute then start the car and have heat. It's rediculous to do this in this day and age. But this is what I as a GM customer have to put up with and as I read this I see I'm not the only one. If I figure out a way to do it I will let you all know.
 
#24 ·
Had the same problem twice.

First time the battery died after the guy installing the tinted windows to my car had the headlights on the entire time. The next day I noticed the heater wasn't getting hot so I took it into the dealership and they charged me $70 for "reprogramming", they said occasionally cars need to be reprogrammed every few months and this was normal. Didn't make sense to me.

Second time I had to unplug the battery in order to replace the Actuator Solenoid Intake/Exhaust, and again the heater wasn't blowing hot air. The circumstance was too coincidental so I took a look on this forum and the solution was so simple.

At least there is this forum for some of us to have an opportunity not to get ripped off by the GM Dealerships that don't have the best interest of the average car guy.

Thank you Chevyguy8893!
 
#29 ·
Hello , I have a 2009 Malibu LTZ, the a/c only blows out of the defrost, I've disconnected the battery to reset it and it only works right for a few days, then it goes back to only blowing out the defrost. The heat and the cold works perfect , but they only blow out the defrost and it keeps fogging up my front window. Does anyone know what part or the name of the part that I need to replace to fix this problem.
Thanks so much guys for your help.
 
#30 ·
Mode door actuator could be bad. That's the actuator that directs airflow. Advanced scanner will read any failure codes stored and is step one.
Disconnecting battery makes the HVAC system reset itself by cycling all the actuators.
My initial feeling is the actuator is binding or failing but I myself would check for fail codes before buying / replacing it.
 
#33 ·
AC system not working, help!

I have a 2010 chevy malibu... when I first got it the a.c. didn't work unless it was on level 3 or 4. Once I turn it on it would make a rattling noise. The dealership that we got the car from never fixed it bc they couldnt figure out what the problem was before they gave it to us.


Then 8 to 9 month's later when I try to use the a.c. and the car comes to a complete stop (red light, stop sign, or in traffic) the car cuts off. Even if the temperature level being on cold makes the car jump and act up, so i always have to keep the temperature level on red. One day it was hot and rainy and I needed to use the defrost and surprisingly the car didn't cut off. I have no idea what to do! im told it could be the compressor or the a.c. sensors on the car. Please help!!!
 
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