Ac Problem?????help
Thread Starter
Racer
Joined: Oct 2006
Posts: 393
Likes: 1
From: Bryan Tx.
Ac Problem?????help
here lately my ac has been shutting off by itself and after about 5 min. it comes back on. ive noticed that it comes on right after the engine starts, but then stops. i have been able to pop it in nuetral AND KILL THE ENGINE AND START IT RIGHT BACK UP AND THE AC WILL COME BACK ON. I CHECKED THE FREON LEVEL AND IT IS OK. ANY IDEAS? THANKS. sorry for the caps, i fat fingered the lock button.
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
A couple of things come to mind...First, its nearly impossible to check the refrigerant level without a professional doing it as it has to be recovered(extracted) and measured, then the exact correct amount to be put back in. Too little or even slightly too much and it won't work. The high and low pressure switches will kill it.
Now another simple possibility is that you have it memorized with the AC off. I've seen it turn on briefly then shut off due to the memory command telling the systems that you wanted it off.
The last remote possibility would be the outside air temperature sensor being somehow bad. If the sensor sees something like 38 degrees outside, the compressor will not run. When thermocouples fail, they usually go to a high temp, but I don't know about these. They might be an RTD too(resistive thermal device) which change reistance with temperature as opposed to a TC that generates micro voltages based on temp.
Now another simple possibility is that you have it memorized with the AC off. I've seen it turn on briefly then shut off due to the memory command telling the systems that you wanted it off.
The last remote possibility would be the outside air temperature sensor being somehow bad. If the sensor sees something like 38 degrees outside, the compressor will not run. When thermocouples fail, they usually go to a high temp, but I don't know about these. They might be an RTD too(resistive thermal device) which change reistance with temperature as opposed to a TC that generates micro voltages based on temp.
Thread Starter
Racer
Joined: Oct 2006
Posts: 393
Likes: 1
From: Bryan Tx.
i had a shop check the freon with a recovery machine and he said that the pressures were right, it didnt need any freon. the outside temp sensor is fine too. could you give me some more info on the memory possibility? thanks
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
If you store the memory for you as the driver, mem 1 or mem 2, if the AC is off when you store the seat positions, radio stations and etc... you will also be storing the fact that the AC is off. If this was the case, you should simply be able to touch the "Auto" button on the hvac control and it should come to life normally. Are you able to set temps on the hvac controller? What about manual fan speeds? I'm wondering if the cable to the hvac controller is partially disconnected. Another thought too, if a professional shop removed and reinstalled the refrigerant via their recovery machine, how did they manage to test it after if the compressor isn't staying on? They should be able to see all the functions although I might suggest a trip to the dealer with a Tech 2 scan tool where they can look at all the sensors together to determine why it isn't staying on. One last quick thought, is the compressor's clutch staying engaged?
Advanced
Joined: Mar 2005
Posts: 90
Likes: 1
From: Tyngsborough Mass
When the a/c is shutting off is it doing at idle or slow speeds or even when your going down the road at speed ? The reason I ask is that as mentioned previously there is a hi pressure switch this shuts the compressor clutch off if discharge refrigerant pressure exceeds the pressure sw. setting, So at idle or slow speeds the fans need to come on to remove the heat from the refrigerant and keep the pressure down. I am not sure exactly what turn the fans on either a pressure sw. wired directly to the fans or to the ECM. If the a/c is even going off at normal road speed then there could be a problem in the computer there is an output that turns the compressor off when you reach a certain RPM or possibly a faulty pressure switch unfortunately as with any intermittant problem some what a pain in the butt to diagnois
Good Luck
Good Luck
Thread Starter
Racer
Joined: Oct 2006
Posts: 393
Likes: 1
From: Bryan Tx.
hey guys, thanks for all the advise. the system goes off even at high speeds, i noticed that the display goes blank when it goes off, and the comp and the blower motor quits. after about 4 mins. it comes back on by mitself and may stay on for an hour before it goes back off and comes back on, and the next time maybe sooner than the last. i did the soldiering repair fix on the digital display and it was working fine. i noticed the stopping and starting about a month ago, and have noticed that it is happening more often.
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Sounds like your hvac controller may have issues. When you soldered whatever connections, maybe you left yourself with a "cold" solder joint? I would open it up again and look for problems or buy another from Ebay and put it in.
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Melting Slicks
Joined: Sep 2006
Posts: 2,736
Likes: 7
From: Redding CA
Having very similar problem as we speak...
Guys,
Not to jump on but I'm actually having a very similar problem right now. Is there any type of a safety mechanism on these things that shut the AC off at too high of a temperature? I live in Redding, CA...it was the 100 degree day today and the car actually got up to 240!!! I was like WTF! So I hopped on the highway and it cooled down to about 235 pretty quickly...I was more okay with that as it was still coming down.
Also, while around town, I would turn the AC on by pressing the button then it would just shut itself off within a couple of seconds. I would then turn it back on only to have it shut off again within a few more seconds?? The coolant temp was also slowing rising...when it hit 240, I shut the AC off and jumped on the highway. When the car settled back down to about 230, I kicked the AC back on...it shut off once then I turned back on and it blew cold all the way to my destination about 10 more miles?
Could it be the AC compressor clutch? Is that something that can be replaced or do I need an entire new compressor?
Thanks so much for any suggestions,
Don Zahner
Not to jump on but I'm actually having a very similar problem right now. Is there any type of a safety mechanism on these things that shut the AC off at too high of a temperature? I live in Redding, CA...it was the 100 degree day today and the car actually got up to 240!!! I was like WTF! So I hopped on the highway and it cooled down to about 235 pretty quickly...I was more okay with that as it was still coming down.
Also, while around town, I would turn the AC on by pressing the button then it would just shut itself off within a couple of seconds. I would then turn it back on only to have it shut off again within a few more seconds?? The coolant temp was also slowing rising...when it hit 240, I shut the AC off and jumped on the highway. When the car settled back down to about 230, I kicked the AC back on...it shut off once then I turned back on and it blew cold all the way to my destination about 10 more miles?
Could it be the AC compressor clutch? Is that something that can be replaced or do I need an entire new compressor?
Thanks so much for any suggestions,
Don Zahner
Thread Starter
Racer
Joined: Oct 2006
Posts: 393
Likes: 1
From: Bryan Tx.
welcome to the gremlin page. i havent noticed that the temp. was too high, today it started again and i gave it the old fonzie side fist to the console and it fired right back up, a couple of times. im going to pull the controller this weekend and check out the guts. on another note i would be worried if my temp climbed as high as yours though, i would make sure you dont have a cooling problem with the engine. jack it up and check your air intake for the radiator, might have some kind of trash or leaves up there
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
To "00Corvette", your's is probably a simple fix. Try cleaning out the debris from the front of the AC Condensor and radiator. Must remember the front air inlets to those is like a vacuum cleaner. Use a compressed air nozzle blowing from the engine side, outward to the front. You will be surprised at how many tiny rocks will come out. Harbor Freight sells a long air wand with a bend at the end that works real nice for this and its cheap...like $4.95. Use it between the condensor and radiator, then on the engine side of the radiator, then lastly, once again between the condensor and radiator.
My suspicion is that you aren't getting airflow through them.
My suspicion is that you aren't getting airflow through them.
Melting Slicks
Joined: Sep 2006
Posts: 2,736
Likes: 7
From: Redding CA
Thanks!
Guys,
I'll blow it all out with air and see if it cools down...I remember there being quite a bit of crap in there when I installed the Vara ram but that was about a year ago now so it's probably all clogged up again.
I'll cruise by Harbor Freight and pick one of those things up and see if I can get this figured out.
Thanks again,
Donnie
I'll blow it all out with air and see if it cools down...I remember there being quite a bit of crap in there when I installed the Vara ram but that was about a year ago now so it's probably all clogged up again.
I'll cruise by Harbor Freight and pick one of those things up and see if I can get this figured out.
Thanks again,
Donnie