a/c freezing up
#1
Cruising
Thread Starter
a/c freezing up
I have a 2001. My a/c freezes up and the air blowing out the vents gradually decreases untill there is very little air coming out of the vents, even tho the fan is still running on high. The compressor is not cycling on and off, just staying on. Does the 01 have a low pressure switch to cycle the compressor or does it have the variable stroke compressor that is supposed to run all the time the a/c is on?
It will run about 40 mins. before it starts freezing up. Any help would be greatly appreciated.
Thanks,
Rans
It will run about 40 mins. before it starts freezing up. Any help would be greatly appreciated.
Thanks,
Rans
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tawc5 (05-17-2016)
#3
Cruising
Thread Starter
I am just seeing if anyone has had this prob. and what they did to fix it.
Thanks,
#4
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St. Jude Donor '08
FIND A NEW AC MAN! Climate Control can NOT cause the evaporator to FREEZE UP.
The Temp Control flaps either open or cover up the AC Evap opening OR open or cover up the heat Coil opening OR a COMBO of both to get temperate air.
There is an orifice restrictor tube in the high pressure Freon hose. It sprays liquid R-134 into the evaporator so it can flash into a GAS. If there is NOT enough pressure in the system, the liquid flashes too quickly and causes the evaporator to freeze the humid air onto the evaporator coil.
Read your DTCs and see if you have any related codes:
DTC P0530 A/C Refrigerant Pressure Sensor Circuit Malfunction
DTC P0531 A/C Refrigerant Pressure Sensor Circuit Range/Performance
DTC P0532 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit Low Voltage
DTC P0533 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit High Voltage
DTC P0534 Air Conditioner Refrigerant Charge Loss
You need enough pressure in the system so that the liquid CHILLS the evaporator. NOT FREEZES IT! There is a VERY fine line between too much pressure and not enough. The service manual is very specific on high side and low side operational system pressures.
BC
The Temp Control flaps either open or cover up the AC Evap opening OR open or cover up the heat Coil opening OR a COMBO of both to get temperate air.
There is an orifice restrictor tube in the high pressure Freon hose. It sprays liquid R-134 into the evaporator so it can flash into a GAS. If there is NOT enough pressure in the system, the liquid flashes too quickly and causes the evaporator to freeze the humid air onto the evaporator coil.
Read your DTCs and see if you have any related codes:
DTC P0530 A/C Refrigerant Pressure Sensor Circuit Malfunction
DTC P0531 A/C Refrigerant Pressure Sensor Circuit Range/Performance
DTC P0532 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit Low Voltage
DTC P0533 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit High Voltage
DTC P0534 Air Conditioner Refrigerant Charge Loss
You need enough pressure in the system so that the liquid CHILLS the evaporator. NOT FREEZES IT! There is a VERY fine line between too much pressure and not enough. The service manual is very specific on high side and low side operational system pressures.
BC
Last edited by Bill Curlee; 02-05-2016 at 12:59 PM.
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tawc5 (05-17-2016)
#5
Cruising
Thread Starter
FIND A NEW AC MAN! Climate Control can NOT cause the evaporator to FREEZE UP.
The Temp Control flaps either open or cover up the AC Evap opening OR open or cover up the heat Coil opening OR a COMBO of both to get temperate air.
There is an orifice restrictor tube in the high pressure Freon hose. It sprays liquid R-134 into the evaporator so it can flash into a GAS. If there is NOT enough pressure in the system, the liquid flashes too quickly and causes the evaporator to freeze the humid air onto the evaporator coil.
Read your DTCs and see if you have any related codes:
DTC P0530 A/C Refrigerant Pressure Sensor Circuit Malfunction
DTC P0531 A/C Refrigerant Pressure Sensor Circuit Range/Performance
DTC P0532 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit Low Voltage
DTC P0533 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit High Voltage
DTC P0534 Air Conditioner Refrigerant Charge Loss
You need enough pressure in the system so that the liquid CHILLS the evaporator. NOT FREEZES IT! There is a VERY fine line between too much pressure and not enough. The service manual is very specific on high side and low side operational system pressures.
BC
The Temp Control flaps either open or cover up the AC Evap opening OR open or cover up the heat Coil opening OR a COMBO of both to get temperate air.
There is an orifice restrictor tube in the high pressure Freon hose. It sprays liquid R-134 into the evaporator so it can flash into a GAS. If there is NOT enough pressure in the system, the liquid flashes too quickly and causes the evaporator to freeze the humid air onto the evaporator coil.
Read your DTCs and see if you have any related codes:
DTC P0530 A/C Refrigerant Pressure Sensor Circuit Malfunction
DTC P0531 A/C Refrigerant Pressure Sensor Circuit Range/Performance
DTC P0532 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit Low Voltage
DTC P0533 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit High Voltage
DTC P0534 Air Conditioner Refrigerant Charge Loss
You need enough pressure in the system so that the liquid CHILLS the evaporator. NOT FREEZES IT! There is a VERY fine line between too much pressure and not enough. The service manual is very specific on high side and low side operational system pressures.
BC
#6
Melting Slicks
Is it on recirculate or outside air? Cold inlet air will also lower evaporator temps. A restricted orfice can also cause low evaporator pressures and allow the refrigerant to boil well below freezing temp of water. The lower the pressure the colder the boiling point that is why a system low on refrigerant will freeze up eventually. What I don't know about car ac systems .....is the blended warm air mixed before evaporator? If it does you could try it on recirculate and raise temp to see if it keeps it from freezing up. Anything that reduces air flow will also lower evaporator temps. Also if your radiator fans are running when air is too cold it will lower head pressure which will also lower evaporator pressure. It's a simple system with many things that could cause the freeze up. Sorry I don't know more about the configuration and controls of auto ac or I may be able to make a better guess.
Oh and your first guess may be it, it seems to me if it is a fixed orfice it would cycle the compressor to keep the pressure in a certain range!
Oh and your first guess may be it, it seems to me if it is a fixed orfice it would cycle the compressor to keep the pressure in a certain range!
Last edited by Forcedvert; 02-05-2016 at 11:44 PM.
#7
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St. Jude Donor '08
Is it on recirculate or outside air? Cold inlet air will also lower evaporator temps. A restricted orfice can also cause low evaporator pressures and allow the refrigerant to boil well below freezing temp of water. The lower the pressure the colder the boiling point that is why a system low on refrigerant will freeze up eventually. What I don't know about car ac systems .....is the blended warm air mixed before evaporator? If it does you could try it on recirculate and raise temp to see if it keeps it from freezing up. Anything that reduces air flow will also lower evaporator temps. Also if your radiator fans are running when air is too cold it will lower head pressure which will also lower evaporator pressure. It's a simple system with many things that could cause the freeze up. Sorry I don't know more about the configuration and controls of auto ac or I may be able to make a better guess.
Oh and your first guess may be it, it seems to me if it is a fixed orfice it would cycle the compressor to keep the pressure in a certain range!
Oh and your first guess may be it, it seems to me if it is a fixed orfice it would cycle the compressor to keep the pressure in a certain range!
That was going to be my very next troubleshooting recommendation (clogged orifice tube) If you put it on the FRESH air (outside air setting, it may extend the time period of the freeze up due to bringing in more warm air from the outside.
BC
#8
Cruising
Thread Starter
Thanks to all who replied.
I would still like to know, does the 2001 have a compressor that is supposed to cycle or is it one of the varible stroke ones that does not cycle on and off???
#9
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BC
#10
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Thread Starter
#11
Heel & Toe
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I have a 2000 with the same issues: Air runs cold for about 20 minutes, then the air volume gradually decreases to nothing. If I turn the A/C compressor off (pushing the A/C button) for about 5 minutes, the air starts blowing again. I can then turn the A/C compressor back on and it will blow cold for about 20 minutes before I have to repeat the above steps. Also, I have noticed it appears only to happen at highway speeds...not around town. I had the A/C system evacuated and refilled to specs. But that didn't seem to help. Thoughts?
#12
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St. Jude Donor '08
I have a 2000 with the same issues: Air runs cold for about 20 minutes, then the air volume gradually decreases to nothing. If I turn the A/C compressor off (pushing the A/C button) for about 5 minutes, the air starts blowing again. I can then turn the A/C compressor back on and it will blow cold for about 20 minutes before I have to repeat the above steps. Also, I have noticed it appears only to happen at highway speeds...not around town. I had the A/C system evacuated and refilled to specs. But that didn't seem to help. Thoughts?
BC
#13
Instructor
I have a 2000 with the same issues: Air runs cold for about 20 minutes, then the air volume gradually decreases to nothing. If I turn the A/C compressor off (pushing the A/C button) for about 5 minutes, the air starts blowing again. I can then turn the A/C compressor back on and it will blow cold for about 20 minutes before I have to repeat the above steps. Also, I have noticed it appears only to happen at highway speeds...not around town. I had the A/C system evacuated and refilled to specs. But that didn't seem to help. Thoughts?
#14
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ITS LOW ON CHARGE or THE ORFICE TUBE IS CLOGGED!!!!!!!!!!!! Plain and simple. A set of gages will show you what the issues is!
VERY HIGH readings on the liquid line high pressure side and low suction side pressures ORFICE CLOGGED!
Low reading on high pressure side low readings on low pressure side low on R-134!
BC
VERY HIGH readings on the liquid line high pressure side and low suction side pressures ORFICE CLOGGED!
Low reading on high pressure side low readings on low pressure side low on R-134!
BC
#15
Instructor
ITS LOW ON CHARGE or THE ORFICE TUBE IS CLOGGED!!!!!!!!!!!! Plain and simple. A set of gages will show you what the issues is!
VERY HIGH readings on the liquid line high pressure side and low suction side pressures ORFICE CLOGGED!
Low reading on high pressure side low readings on low pressure side low on R-134!
BC
VERY HIGH readings on the liquid line high pressure side and low suction side pressures ORFICE CLOGGED!
Low reading on high pressure side low readings on low pressure side low on R-134!
BC
#16
Instructor
Ok... I'm doing it once again. 80 degrees, 65% humidity...LP 55, HP 295. That was in the garage. Once outside it was LP 51, HP 265. I'm assuming those are both high readings? With the car turned off it's LP 97, HP 95.
Last edited by thorn92; 07-13-2016 at 06:32 PM.
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dhirocz (09-29-2023)
#20
Drifting