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Pontiac Grand Prix Climate Control/AC



  • rmozolrmozol Posts: 124
    If you're looking for a permanent, but temporary fix, you can always just disconnect the plug at the compressor too. It wouldn't work when you wanted it to, unless you reconnected it though.
  • dblducedblduce Posts: 58
    im a little confused by this "AC always on" subject. I have had similar incidents, but i dont know if what i experienced is the same thing you have.

    if i use my AC for a day, for example, then the next day, i turn it off (push button and turn fan off), then later go to turn the fan back on, the AC would ALSO come on (button lights up without pushing it). This happened a few times, and it seemed weird that it would come on w/o having to actually push the button. What i found was that if i turned the TEMP knob up to warm/heat, then tried it, eventually i could turn on the fan w/o having the AC come on. So im assuming there must be a connection as to what the temp knob is set to as to when the AC comes on without having to push the button.

    During this past winter, i always had the temp knob turned all the way up, and every time i would turn the fan on, the AC would not come on unless i pressed the button.

    We'll see what happens this spring when i go to use the AC for the first time this year.
  • sahoward1sahoward1 Posts: 19
    The A/C comes on if the outdoor temp is 40 degrees or higher, which is totally absurd. It's not related to the setting inside the car. Somebody screwed up on this, and GM is evidently not willing to fix it. I'm getting nowhere with CAC. And I'm bumming. But unless this gets fixed, it will be my last GM car. And I won't use my GM credit card anymore either.
  • Its probably a liability issue. Someone probably sued GM because they drove around with the interior windows fogged and had an accident and sued. So now it automatically dehumidifies the interior. My 05 Bonneville GXP has the a/c compressor on/off button.
  • teelove1teelove1 Posts: 1
    I am having that same problem with the leaking on my passenger side front and back side. I took it to the dealer and he stated they could fix it for 350.00. He could not explain why or what was leaking or the origin of the problem but he had a price. What the heck!!! What happened with you car. did it cost alot or was it a manufacturer issue. I have a 2004 grand prix gt and it cannot take this leaking water that makes a puddle on my floor. help please.
  • gxpjoeypgxpjoeyp Posts: 38

  • I believe on my "bonneville gxp" which that has the automatic climate control (i guess the g/p has the same) Theres a sensor on the dash that feels the radiated heat coming through the windshield from the sun, and adjusts the variable speed fan blower motor. Maybe you went from shade to sun....I think ive had mine react quickly a few times, but normally theres somewhat of a delay.
  • cdamechcdamech Posts: 31
    It's the same problem of Dirt or Leaves accumulating in the front drainage. The water overflows into the passenger side. Just clean it out but may take some undoing thus chraging $350. You can do this yourself if you have a repair manual. :)
  • c170bc170b Posts: 1
    What does the board look like? Just a regular circuit board? Is it accessible through the glove box? Sorry for so many questions, but I have an a/c blower problem just like this. It will simply not run sometimes and when it runs and shuts down, I can hear a click in the left from panel on the drivers side like a relay or circuit breaker has just opened. I would like to try the resistor and see what happens. Makes sense to me. Do you know the part number for the resistor board?
  • kreiderkreider Posts: 3
    The external temperature as registered on the climate control is way too cold and as a result, won't allow the AC to properly work. Per the owners manual, if external air is sensed below 39F, compressor will not run. It routinely registers below 39 on the hottest summer days, and will actually descend in temperature to as low as 24 when it's actually 95F outside. No manual override, so we just roast and very frustrating. 1. Has anyone seen this previously? 2. Is there an easy fix? 3. Where is this sensor located, and can it be shorted? There is an air temperature sensor in the intake manifold - is this the same that goes to the climate control inside the car? AC works fine when the sensor isn't registering <39, but I've not seen it show higher than 45 this year. Thanks!
  • raynacookraynacook Posts: 1
    I have 1997 Grand Prix with about 120k miles on it. I'm having AC problems (in the middle of a dead-heat summer of course). Last summer my husband recharged the AC and it was fine, blew nice cold air. This year it blows hot. He recharged again and now only the passenger side dash vents (the one beside the door and the one in the middle on passenger side of the dash) blow semi cool air, but all the driver dash vents blow very hot 'outside' Is this a bad compressor? There is also a whining noise that you can hear inside while driving when the AC is on that seems to accelerate with acceleration. The compressor is quite expensive, but if thats the problem, my hubby will do it. Any comments? Suggestions? I don't know what to do other than take the car to garage and be charged off the charts to get this car to blow me some cold air. Thanks...
  • mmxermmxer Posts: 12
    I hear you. I just had my AC redone. I have a 95 grand prix gtp. Old compressor fried. Had to replace the compressor, condencer.... With parts was like $600.
    Whining noise is usually a sigh that the clutch on the compressor might be going. If its still blowing out semi cold air, then the compressor should be ok, and just have to replace the clutch. Its about $100-125 or so, but you need special tools to install it.

    I suggest taking it to a shop just to get an estimate. At least they will tell you whats wrong with it.
  • sprattspratt Posts: 1
    I have a 2000 Grand Prix with the exact same problem; so it makes living Florida, in the summer, not a pleasant experience.
  • My 2004 Grand Prix makes no audibly louder air noise when turning on the recirculate function like so many cars do.. Is this normal, or is something wrong???
  • I found the external air temp sensor and replaced it for 15 bucks. No change. Temp still reads 40 something. 99 in Chicago today. > : - ( <
  • Well when I get in the car today with the new external air temp sensor, the read out was 103 :). The AC did kick on and blow around so cold air. I didn't have far to go and was extreamly hot today so I can't say I fixed it for sure but having the temp right is a big step in the right direction. It was really easy to change. Good luck.... :)
  • where is the switch located? is it easy to replace?
  • momwagmomwag Posts: 14
    I understand that the dash has to be pulled to get to it. Other than that, I don't know.
  • I have the same thing happening in my 2000 Grand Prix. I had a dealer tell me that we needed to replace the climate control system. Just a cool $800 plus labor. Let me know if you found a fix.
  • n8ten97n8ten97 Posts: 3
    My ac has cold air and good air flow but when I accelerate even the least bit the air flow decreases dramatically. Can anyone tell me what would be wrong or what I can replace?
  • mmxermmxer Posts: 12
    My 95 does this. I beleave its suspose to to keep power up. Only does it when I really gun it. Personally I like it. my old car the AC would drain massive power (4c) with [non-permissible content removed] acceleration, no problem with this car.
  • bxdbxd Posts: 186
    One of your vacuum lines is bad. In this year it's common for the line that runs by the battery and down to the vacuum reserve tank to get rubbed through.

    Take the battery out, and look for a fairly thin, hard plastic line. Should run by the battery and down to a ball-shaped tank under the driver's side front end of the car. Follow along it's complete path up through the engine bay. If that's not it, look around engine at other vacuum lines and you should find a bad one. Local auto parts will sell you new line.
  • n8ten97n8ten97 Posts: 3
    I appreciate your help bxd! Il check it out and let you know the results. -n8ten97
  • kreiderkreider Posts: 3
    I did fix this problem with a new temperature sensor - it only cost 7 bucks at the dealership, but took some time to find under the front bumper in one of the air intakes for cooling the radiator, totally out of sight. You can find it by sticking your hand in the intake and feeling around with your palm pointed up, it's connected to the bumper with one of those goofy plastic barbed pins that allow for easy insertion, forceful removal. Worked great for about 3 months, now the AC just doesn't cool yet again, and it isn't the sensor since that still works.
  • kreiderkreider Posts: 3
    Sounds like this may be a compressor issue. It isn't the exterior temperature sensor this time. Any ideas?
  • knepskiknepski Posts: 2
    I recently started noticing this porblem in my '99 GT also. On a recent trip about 3 hours in I noticed the temp reading 68 on a 103 degree day and the AC would blow cool air but not cold. Normally the AC blows really cold air and I rarely run it down on 60 for more than a couple of minutes. I noticed that as I went down hills the sensor tended to correct itself and the AC would blow cold again until I started the next hill climb then the external temp would drop down to 68 again. This happened about 5 or 6 times and eventually it stayed on 68. That was a week ago and now it's on 54 consistently. I'll try the sensor swap and see what happens.
  • Hi,

    I am brand new to this site and read a few threads before I decided to ask my question. I have a '97 Grand Prix GT with a manual control AC System. It has been in the shop three times in the last two weeks and after a few hundred dollars, the AC still is not cold. The shop said the control panel was bad, so I replaced it but this didn't solve the problem. They have stated it is full of freon, everything turns on, but it doesn't get cold.

    Does anyone have any ideas on what to check? I fixed the problem of it blowing out the heater, defrost and dash at the same time. The vacuum hose had come loose under the washer fluid reservoir. This works right now, it switches from max to normal AC, the clutch engages on the compressor, switches to heat, defrost, can move the temp switch from cold to hot and it gets hotter, just won't get cold.....

    I would appreciate any suggestions.

  • Hi, I'm new to this site and I thought that it would be very helpful in helping figure out whats wrong with my blower. My blower only works #5 and not 1-4. What could possibly be the problem?
  • i put freeon in my car it was working fine untill the next day it was blowing hot air
  • I have a 98 GT w/ dual climate control, when I lower the temperature below 74 degrees I hear a squeaking noise like a flapper is trying to close but its jammed. It continues trying to close (squeaking) until I raise the temp above 74 degrees. Anyone have this problem? Anyone know where I can get a diagram of the climate control system?
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