04 Malibu No heat but Air works?


bubrub237
10-23-2006, 10:39 AM
I have an 04 Malibu LS, with cold weather setting in, tried the heater and get no heat. What's weird is, with certain settings I can not turn the air conditioner off. If I have the controls set to defrost, the air condition is the only air that is available and I can't shut it off. I also have to use the recycle compartment air, if I choose to pull in out side air it also always turns on the air condition, not allowing me to shut off the cold air. No matter what settings I put it on I never get warm air. I have checked fuses and all appear to be fine, not sure if the HVAC controls these settings. Any help would be greatly appreciated.

Thanks

tractorboy
10-24-2006, 03:28 PM
most cars, especially durring "defrost" use the AC to provide dry hot air as opposed to damp hot air. I think the AC takes the humiditty out of the air.

make sure you have plenty of coolant, not just in the overflow tank, when the car is STONE COLD , carefully remove the rad cap and make sure the rad is full. you could have a duct door that is not working , blocked heater core ...etc. what does your temp guage read ?

bubrub237
10-24-2006, 07:33 PM
Thanks for replying. My first post was a little miss leading in that the car is garaged. Coolant levels are correct and the gauges read normal on the dash. How would I check or correct a duct door not working? Originally I was thinking along the lines of heater core, but keep coming back to how the climate control settings seem to have a mind of there own. There is a correction to my 1st post and this is the scenero. The only settings I can use that do not automatically turn on the air conditioning are: Outside Air w/ vent, Bi-Level or Floor (these settings still never provide any kind of warm air). If I turn on Recirculation it automatically turns on the air conditioning which can not bet turned off. If I have Outside Air selected and I choose Defog or Defrost it automatically turns on Air Conditioning. When the Air Conditioning light comes on, on any of these settings, pressing it causes it to flash a couple of times then it stays on and the only way to turn off the Air Conditioning is to set it to one of the first set of settings. [My first guess when this started happening was that it was a warning, much like a turn signal or brake light going out, how that turn signal flashes faster than normal]. Any way, your help is much appreciated.

tractorboy
10-25-2006, 06:16 AM
If the AC light is coming on, that is different and something is wrong. Might be the control head. There is a really good article, i think it was this forum, on how to clean the control head. The article was for another symptom that happened to my Malibu and others, where when actually using the AC the light will flicker and go out, and the AC button has to be pushed on / off several times. Your malfunction could be something different, it would not hurt to try. search for it here. I may still have a copy. Basically i think what it was is just disassembly of the control heads and cleaning the elec. contacts with elec contact cleaner or alchol. I will look in the factory manual tonight when I get home for your symptom,,,, i am just leaving for work now.

johnnyt43
10-25-2006, 07:15 AM
The A/c will turn on in defrost and floor defrost modes to dry out the air entering the cab to keep the windwos clean.When you notice you have no heat where is the temp gauge on the car? If your temp gauge is not coming up it could be the thermostat. If the thermostat is not working properly it wont allow the coolant to get hot enough to give heat in the car. The other thing you could check is get the car to operating temp and grab both heater hoses with the car running, if one heater hose is real hot and the other is a lot cooler you have a plugged heater core. If either of those dont fix it you could have a bad temp door actuator. Hope this helps

tractorboy
10-25-2006, 07:28 AM
The A/c will turn on in defrost and floor defrost modes I think I already stated that. I am sure though that the AC light does not come on in defrost. I think something else is wrong.

alblogg
10-25-2006, 05:05 PM
It should not matter if the AC lite is on or not if you turn up the temp to hot and there is hot water getting to the heater core and the door is opening heat should come out one of the selected vents.

tractorboy
10-26-2006, 07:33 AM
I think it does, if you do not have the AC on and you select defrost I do not think that the AC light should come on.

alblogg
10-31-2006, 06:27 PM
I think it does, if you do not have the AC on and you select defrost I do not think that the AC light should come on.
I have not checked in my Malibu yet because my daughter has been driving it since I got the transmission deal figured out but I was riding in my Wifes car today a '07 Pontiac G6 and being cool this morning she had the heat on the floor position with the fresh air selected. I pressed the recycle air button and the AC lite came on. No matter where you put the temp hot or cold the AC compressor was on. It only went off when you went back to outside air but it did not matter where you had the air selector when you had the DEF on the AC lite was on too.

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