I didn't see any recent posts about this, but my 99 Malibu has had a problem with the A/C turning on and off whenever it felt like it any time I tried to use it. After 4 years I finally came across a ridiculous solution that I still can't believe works: pull out on the fan speed knob. I can't remember how I figured it out, but any time I turn on the air now and it doesn't work, or I change from 1 to 2 or something and it goes off, I just pull out on that knob (I don't know the real name for it, just the numbered one) and it never fails - the air will stay on. I have been so tempted to take it in to be "fixed" (if that's possible) but now that I figured this out, as long it keeps doing the trick....Im so glad I didn't waste any money (yet). If anyone else has the same problem and this works, let me know!

Does your blower shut off as well.

I too just bought a 99 Malibu. I turn on the air conditioning the green light of the AC switch goes on, and the air is cold and the blower blows. Then the green light goes out or flashes, and with the blower goimg, it gets warmer in the car. It seems to have a mind of its own. I was told it may be low on freon, but it is very cold while the green light is on. I was wondering if the switch in the climate control unit was bad.

Do you or anyone have a clue?

Nope, my blower stays on, just the cold air goes off. Mine does the exact same thing as yours, there's definitely a short somewhere but since I figured out this little quirk in my car, I haven't had it looked at yet - as long as pulling out on the knob keeps the green light (and cold air!) on, I'm ok. Does that work for you at all? I am curious if it's just my car or what. I definitely don't think it's a freon problem though, since like you said the air is cold when the green light is on. Although if you - or anyone else - do find out what is causing the problem (and how much it is to fix it!), I'd like to know!

99 malubu mine goes to fresh air automaticly sometimes. and once and a while it will turn off but if i turn it on again it will stay on


ps check the vacuum tubes on the back of the controls its the brown an orange ones together are the ones you shold check

I tried pulling on the fan switch and it does help. I found in a brief 19 mile trip I had to do it twice, but that is much better than before. I have removed the knobs and sprayed the area wit contact cleaner. It was working great with the knob in or out. I will test it tomorrow and get back to you.

thanx,

Ok also open the hood start the car turn on the A.C. Check if you hear the A.C. Clutch Kick in if it doesn't then you have to change the coil, ok Stop look turn the car off with your hand move only the clutch if you can turn it 360 then it means that the comperssor is no longer good. See in my 98 I change the switch board but it still threw hot air. I notice the clutch was no kicking when I turn in on. I Thought man o man I going to waste about 400.00 dollars on a new A/C comparssor, and everything you need to make it work. But thanks to My Mech. he said all I needed was a new coil and the A/C should work Now what I recommend if this is what you need go to a A/C pro. because you don't need to take off the comparssor or let the freeon escape becuase a pro like my mech. just jakeup the car took the passager tire off and the black cover and did the whole thing there without wasting more than 100 dollers

This is a pretty common problem. My 2001 is getting worse. Here's one of the fixes. I haven't done it yet, but I plan to soon.

http://www.imcool.com/articles/aircondition/AC_ControllersAreRepairable.pdf

yeah, i did this cleaning and the light stays on now

Had similar problem with 2000 Malibu a couple of years ago. Would switch from internal to external and sometimes switch off. Luckily I took it in just before warranty expired.
Seems it is a common problem with in-dash control unit, which they replaced.

I tried pulling on the fan switch and it does help. I found in a brief 19 mile trip I had to do it twice, but that is much better than before. I have removed the knobs and sprayed the area wit contact cleaner. It was working great with the knob in or out. I will test it tomorrow and get back to you.

thanx,


Just spraying contact cleaner behind the dials and buttons has helped a bunch. I plan to take more of it apart and clean the contacts with spray contact cleaner, that should do the trick as referenced below.

Thanx for everyones help especially the cleaning link.

Just spraying contact cleaner behind the dials and buttons has helped a bunch. I plan to take more of it apart and clean the contacts with spray contact cleaner, that should do the trick as referenced below.

Thanx for everyones help especially the cleaning link.

Try also taking the left and right dials out and bending the small copper spring contacts outward so they exert more pressure on the graphite slide strips. You can also clean the slide strips with alcohol and apply #2 pencil lead as lubricant.