Air conditioning turns on/off by itself
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Air conditioning turns on/off by itself
Whenever I turn on the AC, it starts out fine, nice and cool. Within a couple minutes, the air is still blowing how it should, but it's not cold. The RPMs also jump a little right before the air turns warm. The air will keep turning cold, then warm until I turn off the AC.
Also, whenever I turn the AC on, it seems to put a huge strain on the engine. The RPMs drop a lot, and it seems like I have to push the gas a lot more for any performance. If I push the gas pedal some, the car will barely accelerate and feels like there is a miss. If I go WOT with the AC on, it will take a little bit to accelerate, but then the car acts like it would without the AC on. Any ideas?
Also, whenever I turn the AC on, it seems to put a huge strain on the engine. The RPMs drop a lot, and it seems like I have to push the gas a lot more for any performance. If I push the gas pedal some, the car will barely accelerate and feels like there is a miss. If I go WOT with the AC on, it will take a little bit to accelerate, but then the car acts like it would without the AC on. Any ideas?
Le Mans Master
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Re: Air conditioning turns on/off by itself (vettes rule)
May be the compressor, but could be a low charge, a plugged orifice or faulty cycling switch. The rpm's jump as the compressor cycles off. You can't really tell without hooking up a set of gauges and getting the low & high side pressures. You should also use a scan tool to make sure the ECM is getting the a/c signal and increasing IAC counts to compensate for the load of the compressor. Do look for oil on the hood above the compressor which would indicate that the compressor shaft seal is shot and if it's been running without and oil charge for any length of time, the compressor is probably gone too. If you were getting frost on the windshield when it was working, suspect an evaporator leak.
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Re: Air conditioning turns on/off by itself (SunCr)
Forgot to say the system was charged by a mechanic around a year ago.
I haven't noticed any oil on the hood, but will look next time I use the AC.
I haven't noticed any oil on the hood, but will look next time I use the AC.
Melting Slicks
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Re: Air conditioning turns on/off by itself (SunCr)
May be the compressor, but could be a low charge, a plugged orifice or faulty cycling switch. The rpm's jump as the compressor cycles off. You can't really tell without hooking up a set of gauges and getting the low & high side pressures. You should also use a scan tool to make sure the ECM is getting the a/c signal and increasing IAC counts to compensate for the load of the compressor. Do look for oil on the hood above the compressor which would indicate that the compressor shaft seal is shot and if it's been running without and oil charge for any length of time, the compressor is probably gone too. If you were getting frost on the windshield when it was working, suspect an evaporator leak.
:iagree:
Burning Brakes
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Re: Air conditioning turns on/off by itself (vettes rule)
Also, whenever I turn the AC on, it seems to put a huge strain on the engine. The RPMs drop a lot, and it seems like I have to push the gas a lot more for any performance. Any ideas?
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Re: Air conditioning turns on/off by itself (Rich_01659)
Where are these items in the engine bay, and how can I test to see which is the culprit?
Burning Brakes
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Re: Air conditioning turns on/off by itself (vettes rule)
The condenser is the radiator like thing in front of your engine radiator. one way to tell if this is the culprits (assuming you don't have gauges) would be to get a temperature of the discharge line. if your ac is tripping on high head pressure this line would be VERY hot. you could also reach your hand up under the front and put it against the condenser, it should be hot. BTW what is your normal engine temp.
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Re: Air conditioning turns on/off by itself (Rich_01659)
BTW what is your normal engine temp.
Burning Brakes
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Re: Air conditioning turns on/off by itself (vettes rule)
that engine temp sounds good. Have you removed your radiator and condenser and cleaned them , always a good idea. you may not have a plugged condenser, but still check it. try running a water hose with a good spray in the condenser area (from up under the front) if this keeps it running then the condenser is in need of cleaning. if it is not the condenser it must be the compressor. "HUGE STRAIN" on the engine could be the bearings in the compressor. Low charge would not give you this symptom.
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Re: Air conditioning turns on/off by itself (Rich_01659)
try running a water hose with a good spray in the condenser area (from up under the front) if this keeps it running then the condenser is in need of cleaning. if it is not the condenser it must be the compressor. "HUGE STRAIN" on the engine could be the bearings in the compressor. Low charge would not give you this symptom.
Burning Brakes
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Re: Air conditioning turns on/off by itself (Rich_01659)
I wonder if you ECM is freaking out... The only reason I say this is because there have been a few times when I battery got WAY low and the ECM was doing a lot of funky things, one of which was running the ran while the car was off... Probably just anicdotal, but something to check I guess.
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Re: Air conditioning turns on/off by itself (ninetyfivevette)
I replaced the ECM around 4 months ago when the idle kept screwing up. Fixed that problem
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Re: Air conditioning turns on/off by itself (vettes rule)
There is nothing on the condensor. I'll see if I can spray it down with the hose later today.
[Modified by vettes rule, 10:15 PM 2/18/2003]
[Modified by vettes rule, 10:15 PM 2/18/2003]
Burning Brakes
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Re: Air conditioning turns on/off by itself (vettes rule)
I'm for checking line pressures. If you have fans running, temps under 170, other A/C problems, suspect the A/C coolant fan switch may be open (pressure above around 190 psi)signalling the ECM to turn on fans. With both fan and A/C problems, I'd look for related problems.
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