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Discussion Starter #1
A/C is acting up, sometimes requires me to push the A/C switch a few times to get the compressor going. I will have the car running, A/C selected on and there is no fan noise from under the hood, after driving for 5 min or so I realize my air is not getting any cooler so I cycle the button a few times and voila, instantly cold air.

This is not a "wait for your air to get cold situation", there is a clear and drastic change when I cycle the switch a few times and then all of the sudden it is very clear it has kicked on. Any thoughts?

I'm not dying to take a day (or more) with the car at the dealer, but I have a long road trip coming up next week and am hoping this isn't indicative of a pending A/C failure.

I have done a bit of searching and haven't found anything exactly like this...if a thread already exists feel free to point me to it.

Thanks!
 

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Not cool. Good luck finding the culprit
 

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Questions. Do you have the automatic or manual temperature controls? If automatic, when you press the "snowflake" button for the air-conditioner, does the readout in the upper-right portion of the screen (either a/c on or a/c off) cycle i.e. correspond with each push of the button? Also, has the air conditioning system been leak tested and ensured it isn't running low on refrigerant? Lastly, once the compressor kicks on and cools the air, does it remain on for awhile or does it shut off shortly after coming on?
 

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Discussion Starter #4
Questions. Do you have the automatic or manual temperature controls? If automatic, when you press the "snowflake" button for the air-conditioner, does the readout in the upper-right portion of the screen (either a/c on or a/c off) cycle i.e. correspond with each push of the button? Also, has the air conditioning system been leak tested and ensured it isn't running low on refrigerant? Lastly, once the compressor kicks on and cools the air, does it remain on for awhile or does it shut off shortly after coming on?
1. I have the automatic and when I press snowflake it does cycle the a/c on, off in the display.

2. Have not had it leak tested, assuming that is something you would recommend?

3. Once the compressor is on it stays cold for as long as I drive.

Not sure if that helps narrow it down...Thanks!
 

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1. I have the automatic and when I press snowflake it does cycle the a/c on, off in the display.

2. Have not had it leak tested, assuming that is something you would recommend?

3. Once the compressor is on it stays cold for as long as I drive.

Not sure if that helps narrow it down...Thanks!
Well, at first glance it seems like you might be having an intermittent electrical failure somewhere in the system and they are always the most fun to locate. As far as having the air conditioning system leak tested, answer number three tends to negate the notion since the pressure has to be high enough in order for the air conditioner compressor to cycle on, off and stay running for an extended period of time. However, a mechanic friend recommended to periodically "vacuum" down and recharging the system in order to remove the majority of containment accumulation. Am not fully convinced on the notion, therefore, cannot confirm nor deny the validity of said claim. Come to think of it, the air conditioner refrigerant pressure sensor switch could be experiencing an intermittent failure. For starters, always recommend checking the low hanging fruit first i.e. fuses/relays (properly seated, not blown, nor exhibiting signs of overheating), connectors/wiring (no frays, breaks, insulation worn off nor wiring touching), switches, and etc. You're quite welcome. Good luck
 

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a/c operation

Well, at first glance it seems like you might be having an intermittent electrical failure somewhere in the system and they are always the most fun to locate. As far as having the air conditioning system leak tested, answer number three tends to negate the notion since the pressure has to be high enough in order for the air conditioner compressor to cycle on, off and stay running for an extended period of time. However, a mechanic friend recommended to periodically "vacuum" down and recharging the system in order to remove the majority of containment accumulation. Am not fully convinced on the notion, therefore, cannot confirm nor deny the validity of said claim. Come to think of it, the air conditioner refrigerant pressure sensor switch could be experiencing an intermittent failure. For starters, always recommend checking the low hanging fruit first i.e. fuses/relays (properly seated, not blown, nor exhibiting signs of overheating), connectors/wiring (no frays, breaks, insulation worn off nor wiring touching), switches, and etc. You're quite welcome. Good luck
This may or may not help. I recently had to add some freon to my 2008 GT, but being unfamiliar with the specs of these systems I had to do some research (I have worked on a lot of a/c stuff). Not having access to the actual specs and since I also have a 2009 GT in which the a/c was working fine, I did a static test (gauge test) to find out the pressures. At rest, no a/c operating, ambient temp was 70 degrees, the static pressure was 70 psi (on the suction side - don't mess with the discharge side) in the 2009, but only 60 psi in the 2008, therefor indicating low on freon. Also checked the operating pressure and the temperature coming out of the center vent (system set to max cold and highest speed fan) and observed 38 degrees (yeah, that cold). I now had all I needed to add freon to the 2008. I effectively duplicated the conditions observed on the 2009 car. All is good! So, there is likely a small leak on the 2008, very small since the last service was done on this car about 4 years ago when a schraeder valve was determined to be leaking and was replaced. How does all this help you? I don't know, but I suggest that the low pressure switch on the suction line may be going bad, making intermittent contact. If you have someone that knows how to hook up a gauge set (do so on the suction line - easy to get to) the access port is on the driver side on the large line - the cold one - don't mess with the high pressure line - the hot one - you can easily get seriously hurt. Also, always wear long sleeves, good leather gloves and safety glasses to avoid injury from cold or hot freon. The suction line will have a gas, but the high pressure line will be hot liquid - very dangerous!! You can put a gauge set on that line, but it's unnecessary. If it is determined that the low pressure switch is at fault let a dealer or knowledgeable a/c mechanic replace it. The system will need to be evacuated (you need the proper pump) and briefly opened to the air to replace the switch and the system re-evacuated before re-installing freon. Hope this helps, but please do not get yourself hurt if you don't know what you are doing!

grandpop09
 

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This may or may not help. I recently had to add some freon to my 2008 GT, but being unfamiliar with the specs of these systems I had to do some research (I have worked on a lot of a/c stuff). Not having access to the actual specs and since I also have a 2009 GT in which the a/c was working fine, I did a static test (gauge test) to find out the pressures. At rest, no a/c operating, ambient temp was 70 degrees, the static pressure was 70 psi (on the suction side - don't mess with the discharge side) in the 2009, but only 60 psi in the 2008, therefor indicating low on freon. Also checked the operating pressure and the temperature coming out of the center vent (system set to max cold and highest speed fan) and observed 38 degrees (yeah, that cold). I now had all I needed to add freon to the 2008. I effectively duplicated the conditions observed on the 2009 car. All is good! So, there is likely a small leak on the 2008, very small since the last service was done on this car about 4 years ago when a schraeder valve was determined to be leaking and was replaced. How does all this help you? I don't know, but I suggest that the low pressure switch on the suction line may be going bad, making intermittent contact. If you have someone that knows how to hook up a gauge set (do so on the suction line - easy to get to) the access port is on the driver side on the large line - the cold one - don't mess with the high pressure line - the hot one - you can easily get seriously hurt. Also, always wear long sleeves, good leather gloves and safety glasses to avoid injury from cold or hot freon. The suction line will have a gas, but the high pressure line will be hot liquid - very dangerous!! You can put a gauge set on that line, but it's unnecessary. If it is determined that the low pressure switch is at fault let a dealer or knowledgeable a/c mechanic replace it. The system will need to be evacuated (you need the proper pump) and briefly opened to the air to replace the switch and the system re-evacuated before re-installing freon. Hope this helps, but please do not get yourself hurt if you don't know what you are doing!

grandpop09
A very well stated post. Also, don't rely on those d-i-y air conditioner re-charge kits sold nationwide when trying to verify low side pressure. Used one once and was very fortunate things turned out okay since the accuracy of the readout is at best "questionable". However, am sure there are people that swear by them and subsequently have used them on hundreds, if not thousands, of vehicles all without any adverse effects. On the topic of refrigerant, have been told not to use the anything containing a stop leak additive since it could negatively impact the system. Can someone shed any light on the notion? Someone with both the proper knowledge and equipment is definitely the way to go when servicing an air conditioning system.
 

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I have an a/c chart this may be some helpful information for all
 

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additional info

A very well stated post. Also, don't rely on those d-i-y air conditioner re-charge kits sold nationwide when trying to verify low side pressure. Used one once and was very fortunate things turned out okay since the accuracy of the readout is at best "questionable". However, am sure there are people that swear by them and subsequently have used them on hundreds, if not thousands, of vehicles all without any adverse effects. On the topic of refrigerant, have been told not to use the anything containing a stop leak additive since it could negatively impact the system. Can someone shed any light on the notion? Someone with both the proper knowledge and equipment is definitely the way to go when servicing an air conditioning system.[/QUOTE

Assuming you have the needed knowledge and a gauge set, follow this procedure: close all the gauge set valves; hook up the lines - the low pressure side (suction side - blue handled valve; center - freon source - yellow handled valve; high pressure side - red handled valve - no need for hose to be connected on this one) and be sure that you purge the lines briefly to remove any air, i.e: after hooking up the gauge set, open the suction side which is now attached to the suction connection on the car, and purge several seconds (you can do this easily by opening the discharge (red handled) valve - re-close, then open the yellow handled valve to purge from the freon source - (can or canister) re-close. You do not want to introduce any air into the system! Now you can follow the procedure I described in the post above. The chart supplied by the subsequent poster (thank you!) bears out my results as stated - 37-38 degrees at the center vent.

I think that many people who have used the freon kits may have introduced a little air into their systems - not good.

I would not personally use a stop-leak freon source because it will definitely not stop a schraeder valve leak. Other types of leaks tend to get worse, especially on the high pressure side where most leaks occur. It's a good marketing ploy, but not very good technically speaking.

grandpop09
 

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Thanks for the chart

I have an a/c chart this may be some helpful information for all
By the way I also have an IOM 2008 with every option that was available in 2008, plus some additional accessories purchased by the first owner. Unfortunately my windshield was hit with a rock and will be replaced, hopefully this coming Monday. Since the Saint Gobain Sekurit is no longer available, a Pilkington has to be used - be aware there are two levels of those, the higher cost one (approx. $400) is supposed to have the accoustic qualities of the SGS unit. Maybe? No other choices are available.

grandpop09
 

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I'm resurfacing this thread. I now have the same exact issue as OP. I have to turn the AC on and off a couple times till it works, then it works normal for the rest of the day. Air is nice and cold. Any ideas?
 
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