I did not know that the test is performed all the time, and all the time makes sense because the compressor could sieze any time, but once compressor is shutoff does the car not need to be turned off and then back on for it to work again ? Is it possible that your Klima relay has failed in some very desirable way, atleast for some ?

So then the problem may still lie in the speed sensors. You can test the speed sensor outputs at the Klima relay socket. somewhere in this thread I have the steps to test the sensor signals.

Or may be the relay itself, but check that shorting pins 5 and 7 gets rid of the problem.

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Saumil S. Patel