In the later model MBs, you can use the N22 control panel to readout the various parameters and 'watch' how well your ACs works. The details for my car are shown in MENU#15 under "Operational Checks". This procedure works for most MBs.

Press the "REST" button until the panel indicators change and display the key internal parameters. Two that show you well your AC is functioning is #5 (evap temperature) and #7 (compressor pressure in BAR).

For example, there was a '02 E430 at my tech's shop and I checked it out. From a cold start (80 deg day), The evap went from startup temp (70F) to 40F in 15 secs (cold engine). Then a few seconds later, it continued to go down to 33F and cycled between 35 to 39F even as the engine started to warm. That's my definition of a 'good' working AC!

I hope to get my AC to do this again.

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Regards . . . . JimF
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'94 S500 Cpe

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