If the A/C compressor belt is spinning, does this mean that it is ok?>>>
09-09-2007, 06:43 PM
#7
Hard to diagnose without seeing but here are a few facts that might help you.
The compressor has a magnetic clutch. The pulley always turns. The center of the pulley (clutch plate ) should turn when AC is on. If it is not turning then the problem is most likely related to a pressure switch or a loss of refrigerant. If the clutch cycles in and out repeatedly every few seconds then the problem is almost certainly low refrigerant. A pressure switch looks for pressure on the low side (suction) of the refrigerant circuit. If pressure is too low (30- 40 ps1) the switch will turn the magnetic clutch off. When the compressor stops the pressure will rise as the high side of the circuit equalizes pressure with the low side. The low pressure switch will close and the compressor will run again until it "sucks" the pressure down below that switch setting again. Over and over and over. If there is enough refrigerant, the pressure on the low side stays higher and that switch never opens and stops the compressor.
If the center (clutch) of the pulley is turning but no cooling is taking place that's probably bad. (compressor) But most likely it would be noisy or even lock up and smoke the belt. Pressure can't be checked without refrigeration guages. "Some" pressure is not necessarily enough.
Since your cooling stopped suddenly a slow refrigerant leak is not the likely cause. A bad pressure switch, a bad magnetic clutch, or even a blown fuse or a fusible link to the clutch are all likely culprits. (Does anyone know if the TT has a fusible link for the compressor clutch? )
Good luck with your problem. Anyone well versed in auto refrigeration should be able to diagnose it for you. It might however take a VW Audi specialist to track an elusive electrical issue, if thats what is wrong.
If the center (clutch) of the pulley is turning but no cooling is taking place that's probably bad. (compressor) But most likely it would be noisy or even lock up and smoke the belt. Pressure can't be checked without refrigeration guages. "Some" pressure is not necessarily enough.
Since your cooling stopped suddenly a slow refrigerant leak is not the likely cause. A bad pressure switch, a bad magnetic clutch, or even a blown fuse or a fusible link to the clutch are all likely culprits. (Does anyone know if the TT has a fusible link for the compressor clutch? )
Good luck with your problem. Anyone well versed in auto refrigeration should be able to diagnose it for you. It might however take a VW Audi specialist to track an elusive electrical issue, if thats what is wrong.
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09-09-2007, 08:39 PM
#8
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Check to see if you have 12v to the clutch when the ac should be on>>
If you do = bad clutch or compressor
If you don't = blown fuse, bad pressure switch, other sundry electronic issues
If you don't = blown fuse, bad pressure switch, other sundry electronic issues
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