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Chevrolet Malibu Climate Control/AC Issues



  • gonogogonogo Posts: 871
    A good start is check the vacuum lines under the hood. Start at the intake manifold and trace to the reservoir, from reservoir to the firewall.
  • imidazol97imidazol97 Crossroads of America: I70 & I75Posts: 18,045
    You need the factory service manual for that model and air conditioner system. You might have vacuum tubes and you might haveelectrical components moving vanes.

    You might look for the vacuum storage tank that holds vacuum while the motor is accelerating in the engine compartment. Right after motor is turned off pull tube off the housing and you should hearair rushing in. If not, you could have a crack in it, a leak inside the tubing inside the passenger compartment or a tube off somewhere.

    If you have vacuum to the interior of the car, then the problem may be the control that switches the vacuum to various vacuum motors that pull the vanes inside the box to make the air do the right thing.

    The air goes to the defroster if there's no vacuum in the system as a safety mode. Then you can always "see" to drive the car. But a vane closes off the air to the defroster and makes it come out the dash vents. So if that motor, or tube, or no vacuum condition doesn't have the right vacuum, you have defrost only. Time for some upside down troubleshooting under the dash.

    Try for factory service manuals or EBay (yuck).
  • pulliagspulliags Posts: 3
    Need a little help with this one. I've searched the forum, but this appears to be a little different than what other's have experienced. When I initially start my 99 Malibu the AC works fine at all 5 settings. After driving for about a half hour, the force of the air flow coming out of the vents starts weakening. After about another 5 minutes, the air is barely blowing at all even at level 5; but still feels relatively cold. On the 95 degree days where I live I need the AC to keep blowing. I've had the blower motor replaced, but that didn't do a thing. Any ideas? Thanks!! :)
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 44,404
    Hmmm...sounds like a vacuum failure at one of the "blending doors" that directs air flow. I bet you feel cold because all the AC is going to the floorboard area. Did you check to see if it's blowing strong down there?


  • pulliagspulliags Posts: 3
    I don't really feel cold because the air flow doesn't keep up with the 90 degree temperature. I haven't checked to see if I can feel it coming out in the floorboard area. I'll give that a shot. Why would it work at first, but then fail after 30 minutes of driving?? Thanks!!
  • shadow5599shadow5599 Posts: 101
    Not sure if it has an air filter but I know someone with a Venture minivan and airflow pretty much came to a stop and that's what was wrong. Once the filter that resides behind the glovebox was changed all was normal again.
  • imidazol97imidazol97 Crossroads of America: I70 & I75Posts: 18,045
    Sounds like it could be a decrease in vacuum or a problem in the control that switches the vacuum or a failure in one of the vacuum "motors" that move the vanes.

    Also could it be the evaporator is freezing up and partically blocking the flow of air through it? With low charge the ACs sometimes run colder than normal. Does your AC click in and out several times a minute when idling right after driving it? You can hear the clutch engage if you have a window down.

    One way to check for freezing is to turn off AC and just use vent for a few minutes. If the air flow increases again that would be the ice melting from the evaporator letting air through easily again.
  • pulliagspulliags Posts: 3
    I have noticed on several occasions that I've seen a cold mist blowing out of the vents after the air has slowed out of the vents. This isn't every time, but has happened.
  • gonogogonogo Posts: 871
    Try this, when it is not blowing very strong shut off the A/C for a few minutes with the blower on, if the air flow comes back your evaparator is icing up.
  • imidazol97imidazol97 Crossroads of America: I70 & I75Posts: 18,045
    >One way to check for freezing is to turn off AC and just use vent for a few minutes. If the air flow increases again that would be the ice melting from the evaporator letting air through easily again.

    I already suggested that to pulliags.

    What result did you get?
  • dbenniondbennion Posts: 1
    I see many different issues with the air conditioners but nothing like what is happening in my Malibu. The air conditioner works great when the AC light is illuminated, but the light turns off at random. When I notice the air is not blowing cold anymore, I will press the AC button several times until the light comes on and I can hear the compressor start again. It is very temperamental. It will work fine until I turn it from 3 to 2 then it will shut off but will come back on if I switch it back to 3. Is it a fuse issue or something else? Any Ideas??? Thanks
  • cwfinncwfinn Posts: 1
    I had the same problem. It turned out to be the wiper on the back of the terperature control. I opened up the control unit and bent the wiper to make a stronger contact with the board and it has worked fine since (2 years).
  • wxman4wxman4 Posts: 53
    My '99 had a problem with the little light in the AC button going off and on by itself. AC was only working when the light was on. The fix was to replace the control head in the dash (the actual panel with the knobs and buttons). Fairly easy to replace, but over $200 new for the part.

  • kurtamaxxxguykurtamaxxxguy Posts: 1,714
    ...but I am really curious as to if the redesigns the Malibu got for '04 and onward will head off all these AC problems that the earlier Malibus have had.

    Are the switches, servos, etc. substantially different in the '04's ..vs.. earlier Mailbus?
  • e2helpere2helper Posts: 1,002
    I am not familar with the AC problems with previous body style Malibu other than the blower resistor card.

    The main components like actuators and control head are substantionally different. Old body style had mostly vacuum actuators while new one has all electric motors. The blower motor is a blower motor don't know how different it is. The base AC system still has a resistor card but is most likely a new design. The auto AC system uses an electronic module in place of the blower resistor which provides more blower speeds.
  • gonogogonogo Posts: 871
    Glad to read I have a resistor motor control, modules are not cheap.
  • I have exactly the same problem. Thank you for sharing that bending the wiper on the control unit fixed it. However, can you also tell me how to get the control unit out and apart. I don't want to destroy the plastic parts trying to figure this out myself. Your experience and help is much appreciated. (I just wasted $20 replacing the compressor relay thinking that might be the problem. :( )
  • i have a 97 malibu with 3.0l and it blows fuses that control gauges on dash with the ac off even can anyone give any ideas?if i leave the relay out the gauges are ok only when i put the relay back in it will blow the fuses is that the body control modual or somewheres else?
  • e2helpere2helper Posts: 1,002
    What relay?
  • its the ac relay under hood in main fuse box
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