A/C cycling on and off
07-25-2005, 03:29 PM
#1
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Location: Novi MI
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A/C cycling on and off
Some days the compressor turns on other days it doesn't.
The charge is good.
On days that it does work, when the air is on max it gets cold then warm then cold then warm, like the compressor is cycling. I have a feeling its the pressure switch.
What are the possibilities?
The charge is good.
On days that it does work, when the air is on max it gets cold then warm then cold then warm, like the compressor is cycling. I have a feeling its the pressure switch.
What are the possibilities?
07-25-2005, 03:33 PM
#2
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Location: San Antonio TX
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Re: A/C cycling on and off
Mine did the exact same thing in my beater, it turned out to be the cycling switch. cheap easy fix, but with the air conditioner you never know what could be wrong, worth a try though....
07-25-2005, 06:19 PM
#4
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Re: A/C cycling on and off
Originally Posted by Jdude540
Mine did the exact same thing in my beater, it turned out to be the cycling switch. cheap easy fix, but with the air conditioner you never know what could be wrong, worth a try though....
Could you possibly mean the relay???? or do you mean the thermal expansion valve??????JDMZ28, have you scanned it for DTCs? AC codes will not set the SES. If it is the pressure switch, the PCM should set a code. Currently I have that problem with mine. A 61 that is, not necessarily the pressure switch. I suggest you scan it and see and proceed from there. Remember, R134 aint like R12. There aint much there to begin with. It takes very little loss to get it low. The clutch circuit, the relay circuit, the pressure sensor circuit and the evaporator sensor circuit are all monitored by the PCM.
07-25-2005, 06:46 PM
#6
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Re: A/C cycling on and off
Originally Posted by slopokrodrigez
Could you possibly mean the relay???? or do you mean the thermal expansion valve??????JDMZ28, have you scanned it for DTCs? AC codes will not set the SES. If it is the pressure switch, the PCM should set a code. Currently I have that problem with mine. A 61 that is, not necessarily the pressure switch. I suggest you scan it and see and proceed from there. Remember, R134 aint like R12. There aint much there to begin with. It takes very little loss to get it low. The clutch circuit, the relay circuit, the pressure sensor circuit and the evaporator sensor circuit are all monitored by the PCM.
07-25-2005, 07:03 PM
#7
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Location: Kearney, Nebraska
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Re: A/C cycling on and off
If your expansion valve goes bad, your a/c will still work, it just wont cool. It is moving air and you will have pressure, but it wont be mixing enough freon to cool the air.
07-26-2005, 03:43 PM
#11
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Re: A/C cycling on and off
It does get cold when the compressor is on, it just keeps cycling on and off. The pressure was fine when I hooked up to the the fitting on the low side. How do I bypass the low pressure sensor? ANYONE?
07-26-2005, 08:02 PM
#12
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Location: Statesville NC
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Re: A/C cycling on and off
again. you say pressure was fine. Tell me what "fine" is. don't go jumping switches. You will end up gernading your compressor. Pressure information is NEEDED to diagnose AC problems.
07-27-2005, 09:18 PM
#13
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Location: Upstate New York
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Re: A/C cycling on and off
Take the top rad plate off and make sure the top 3rd of your condenser isn't plugged with crap.
I just replaced my condenser with a new one I got on ebay for 120.00 shipped, and the rad support chin spiole that channels air up into the cooling system.
Mine had gotten torn off a while ago.
My car was also running hot.
May not be your problem but it was mine.
I just replaced my condenser with a new one I got on ebay for 120.00 shipped, and the rad support chin spiole that channels air up into the cooling system.
Mine had gotten torn off a while ago.
My car was also running hot.
May not be your problem but it was mine.
08-02-2005, 04:18 PM
#14
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Re: A/C cycling on and off
Ok its been working for the past few days. Heres what I've noticed: When I first turn on the air its hot. Then for about 10 minutes it gets cold hot cold hot cold hot. The compressor is not turning on and off, which stumps me. After about 15 minutes it gets really cool like nothing wrong. Don't understand. BTW Pressure is at 50 psi at idle but drops to like 35 at 2000rpm. The readings were taken from the port where you fill the freon.
08-03-2005, 09:02 AM
#15
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Re: A/C cycling on and off
Doesn't SEEM to be a charge issue. What is the pressure when the vent temp is going hot-cold? And what is the evap temp reported by the PCM during this time? Does it track the vent temp? It might not be a refrigerant issue. And since you say the compressor stays on during the hot-cold, it's probably not an evap temp sensor issue. I guess it points toward the expansion valve. Check the temp of the inlet and outlet evap lines and see if there is extensive frost on one of them, or a serious temperature difference between them.