Ac blows ambient temp only
08-20-2016, 10:39 PM
#1
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2000 S430
Ac blows ambient temp only
Desperate need of advise on this one.
Ac blows only ambient air temp
heater works good
Power to compressor 12v
Cleaned duo valve
Refrigerant has been evacuated and filled to spec
Cannot tell if clutch is engaging due to cover please help
Ac blows only ambient air temp
heater works good
Power to compressor 12v
Cleaned duo valve
Refrigerant has been evacuated and filled to spec
Cannot tell if clutch is engaging due to cover please help
08-21-2016, 05:38 AM
#2
Super Member
Do you still get condensate dripping after driving the car? If not, the compressor is not engaging. Unless you live in the Mojave, even A/C that doesn't have to work will produce condensate. For more direct confirmation, you can feel the A/C lines and see if they are getting cold.
Last edited by Jack_88; 08-21-2016 at 05:40 AM.
08-21-2016, 09:34 AM
#3
MBWorld Fanatic!
The W220 does not use an AC clutch. The compressor turns with the engine - the computer controls the amount that the compressor pumps by varying the displacement inside the compressor.
Make certain that the tiny red light located on the AC control button is OFF. If the red light is ON, the compressor is off - not pumping refrigerant.
If there is no red light, make sure that the HVAC is turned on, then run the engine for a couple of minutes. Feel the metal lines near the compressor - one should be hot, one should be cold. If not, the compressor is not working.
If the compressor is not working, the compressor may be locked up and the drive may be sheared. The drive pulley is connected to the compressor shaft thru rubber cushions. If the compressor seizes, the rubber cushions shear to allow the serpentine belt to keep running. (If the belt stops, the engine will shortly stop due to catastrophic overheating.)
You can, with difficulty, tell if the compressor is turning. Use a good light to watch the very small bolt in the center of the drive pulley - if it is not turning, the compressor is not turning.
If the little red light is ON, you will have to use the STAR system (or a good substitute) to reset the system. If the system won't reset, the computer sees a serious problem, and has turned the compressor off.
Make certain that the tiny red light located on the AC control button is OFF. If the red light is ON, the compressor is off - not pumping refrigerant.
If there is no red light, make sure that the HVAC is turned on, then run the engine for a couple of minutes. Feel the metal lines near the compressor - one should be hot, one should be cold. If not, the compressor is not working.
If the compressor is not working, the compressor may be locked up and the drive may be sheared. The drive pulley is connected to the compressor shaft thru rubber cushions. If the compressor seizes, the rubber cushions shear to allow the serpentine belt to keep running. (If the belt stops, the engine will shortly stop due to catastrophic overheating.)
You can, with difficulty, tell if the compressor is turning. Use a good light to watch the very small bolt in the center of the drive pulley - if it is not turning, the compressor is not turning.
If the little red light is ON, you will have to use the STAR system (or a good substitute) to reset the system. If the system won't reset, the computer sees a serious problem, and has turned the compressor off.
