94 S500 Coupe A/C PUSHBUTTON TURNS OFF...
 

I have a 94 S 500 in the bay that has a problem with the A/C system. I have found that the A/C pushbutton does not stay on for more than 20 to 60 seconds at a time. I have found that the pushbutton will also go into a fixed mode where it doesn't recognize any input from pushing any of the buttons. I have found that the Climate control will sometimes stay energized even after the car has been turned off. It will continue to run the blower and the A/C clutch will still be engaged with out any key in ignition. I pulled out my scanner and found the two following codes.

84 Intermittent switchover valve block (y11/3)

85 Switchover valve block (y11/3) Fresh/recirculating

I have removed the Climate Control and replaced it with a known good one and what I have found is that the push button does the same thing except stay on with the key out of the ignition. I believe this car may have two prolems. 1) A/C pushbutton because the a/c does work better now except for the cutting off every 20 to 60 seconds. 2) The switchover valve has a problem within itself causing the A/C pushbutton to receive an incorrect signal. Has anyone experienced anything like this before on any other 140 chassis 92 thru 95.

Thanks for the help in advance

Melvin