2002 ML320 a/c compressor not disengaging
07-28-2019, 01:08 AM
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2004 E320 4matic Wagon, 2002 ML320
2002 ML320 a/c compressor not disengaging
Hello newbie here first time posting, I need some help with a/c on W163 After compressor locked up, ripped the serpentine belt and idler pulley I decided to replace most a/c components as my ML has already 194000 miles.
All freon was lost so I did not needed to evacuate to empty out. I have replaced a/c compressor, condenser, drier, expansion valve and all little O rings along all the connections. I vacuum the system to make sure there are no leaks, system hold pressure perfectly.
System calls for 750 grams of freon, I have recharge the system with 2 cans each around 340 grams so guessing I have around 680 grams of freon. Within 5-10 minutes I have 60 F at the vent nice and cold, but the auxiliary fans are on and a/c compressor is not disengaging,
High pressure is around 250 and Low pressure 45.
My question is would it be possible that pressure / temperature switch located on the high side line near the drier is faulty and not sending signal to let the compressor known the pressure or temperature is building up, I hate to bust the a/c compressor !!!
Are there any other pressure switches on this system ?
Any thoughts or ideas would be highly appreciated.
Thank you
Robert
All freon was lost so I did not needed to evacuate to empty out. I have replaced a/c compressor, condenser, drier, expansion valve and all little O rings along all the connections. I vacuum the system to make sure there are no leaks, system hold pressure perfectly.
System calls for 750 grams of freon, I have recharge the system with 2 cans each around 340 grams so guessing I have around 680 grams of freon. Within 5-10 minutes I have 60 F at the vent nice and cold, but the auxiliary fans are on and a/c compressor is not disengaging,
High pressure is around 250 and Low pressure 45.
My question is would it be possible that pressure / temperature switch located on the high side line near the drier is faulty and not sending signal to let the compressor known the pressure or temperature is building up, I hate to bust the a/c compressor !!!
Are there any other pressure switches on this system ?
Any thoughts or ideas would be highly appreciated.
Thank you
Robert
Last edited by Tojestsila; 07-28-2019 at 01:39 AM.
07-28-2019, 02:40 AM
#2
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but the auxiliary fans are on and a/c compressor is not disengaging, The fans are supposed to be on and why would the compressor disengage if the A/C was on. Confused by your wording.
07-28-2019, 01:21 PM
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2004 E320 4matic Wagon, 2002 ML320
Hi Maj, Dundee
Sorry for the confusion, Yes the auxiliary fans are running non stop, the pressure on my gauges showing 250 high and 45-48 low, but the compressor is not shutting off in order to lower the pressure which is building up.
So is this normal for auxiliary fans to run continuously and pressure on high / low stay the same ?
Sorry for the confusion, Yes the auxiliary fans are running non stop, the pressure on my gauges showing 250 high and 45-48 low, but the compressor is not shutting off in order to lower the pressure which is building up.
So is this normal for auxiliary fans to run continuously and pressure on high / low stay the same ?
07-29-2019, 10:24 PM
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2004 E320 4matic Wagon, 2002 ML320
I used the " DuPont R-134a Suva A/C Automotive Refrigerant Freon 340g in each can. Bought them on Amazon while back 3 for $19.95
I tried posting the picture but it won't load - I am sorry.
As far as the A/C goes, works and cools well temperature at the vent 57-58 F.., gauges just sitting stable at about the same pressures, auxiliary fans are running non stop which I have not experience with the old compressor in the past. My compressor does not have the clutch on the front so I can not observe the engaging on and off.
I should have change the pressure switch while I had the entire system apart but will do it in the future, I need to buy my own Recovery Machine.
I tried posting the picture but it won't load - I am sorry.
As far as the A/C goes, works and cools well temperature at the vent 57-58 F.., gauges just sitting stable at about the same pressures, auxiliary fans are running non stop which I have not experience with the old compressor in the past. My compressor does not have the clutch on the front so I can not observe the engaging on and off.
I should have change the pressure switch while I had the entire system apart but will do it in the future, I need to buy my own Recovery Machine.
07-30-2019, 12:02 AM
#6
MBWorld Fanatic!
Copy and paste your original post and post it on this forum. Read this post on that forum.
https://www.benzworld.org/forums/w163-m-class/
https://www.benzworld.org/forums/w16...0-ac-work.html
https://www.benzworld.org/forums/w163-m-class/
https://www.benzworld.org/forums/w16...0-ac-work.html
Last edited by Maj. Dundee; 07-30-2019 at 12:11 AM.
