The clutch is closed and stays closed the whole time. After the first time of revving the engine and it started cooled it cooled after that even at idle. It's strange. Anyway I will probably go ahead and replace the expansion valve at some point and see what happens. I assume I will need to replace the drier again when I open up the system. There is not a site glass on this vehicle that I am aware of.
Sent from my iPhone > On Mar 15, 2016, at 1:12 AM, archer75--- via Mercedes <mercedes@okiebenz.com> > wrote: > > The possibilities I can think of are: > 1. Debris from previously destroyed compressor periodically blocking open > either the expansion valve or a valve in the compressor. > > 2. Low voltage to clutch or electrical control system at low rpm. (Wiring > corrosion? Defective relay? Defective PC board?) > > 3. Feature that turns off compressor while idling (if ML has that feature). > > 4. Excess or insufficient oil in the system. (rare.) > > Is the clutch opening and closing? > Can you watch it when you rev engine and A/C starts working? > Can you verify that freon is flowing past the sight glass when A/C is not > cooling? (This might verify that a valve is stuck open.) > > If you can see the AC clutch, see if it is closing when the engine is revved. > If so, that might point to an electrical problem rather than a mechanical > problem. If the clutch is closed when AC is not cooling, that might point to > a mechanical problem > > Here is a diagnostic link: > http://www.eclassbenz.com/?s=mercedes+ml320+is+e+class%3F > > Hope this helps. > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > "Kaleb C. Striplin wrote: >> The compressor is running the whole time. Clutch and compressor new and >> nothing is slipping. I just put the gauges in it and it has a static >> pressure high and low the same. I revved the engine up and it is like it >> woke it up and pressure started acting normal and it started cooling. > >>> "Kaleb C. Striplin wrote: >>>> Last summer the ac in the ML started only working part time even though >>>> compressor was running. It got worse to the point that it never cooled. >>>> Hooked gauges up and it was not building any pressure even though properly >>>> charged. I ordered a new compressor and drier and swapped it out and >>>> charged. We were in winter then. Now it is hot the last few days and it's >>>> the same thing compressor running, just blows outside air, no cooling at >>>> all then all the sudden will work fine for a while. I am now suspecting >>>> the expansion valve is sticking or something. That's about all else it >>>> could be. If compressor was bad I would think it would never work at all. >>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >>> Compressor clutch slipping or working intermittently? >>> (Can you watch it while it's running?) Did you replace it as well as the >>> compressor? >>> >>> Slipping belt? >>> >>> Periiodically sticking low pressure switch? >>> >>> Low pressure switch triggered periodically by low freon. >>> What are the gauge pressures? >>> >>> Gerry >>> >>> >>> >>> _______________________________________ >>> http://www.okiebenz.com >>> >>> To search list archives http://www.okiebenz.com/archive/ >>> >>> To Unsubscribe or change delivery options go to: >>> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >> >> _______________________________________ >> http://www.okiebenz.com >> >> To search list archives http://www.okiebenz.com/archive/ >> >> To Unsubscribe or change delivery options go to: >> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >> >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 2015.0.6189 / Virus Database: 4542/11815 - Release Date: 03/14/16 > > > -- > arche...@embarqmail.com <arche...@embarqmail.com> > > _______________________________________ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
