Hi
The AC on my 190E works great most of the time, I have checked all the usual things, Presures, compressor control, coolent & evap temp sensors, belt tension, comp clutch, all appear to be with in limits.
What is happening is that the AC comes in some times for half hour or maybe longer and then just quits then some time later it will come on again or if I stop the car and turn it off some times it will come on again some time not.
The problem seems to be worst when the ambient temps are higher above 75F.
It will work all the time when I ground pin 10 on the comp control and it will produce vent temps of 40F or less if I let it.
When I first bought the car the AC would not run at all, I thought it was th PBC so I opened it up to see if any thing was a miss but found nothing so I put it back in plugged it in and it works some times.
Do any of you folks have any suggestions.
Thanks
Chuck

I posted a long test procedure a few days back, may or maynot apply to 190E but search for my name and see if the climate control relay pins are similar. There are a whole bunch of sensors hooked up to the climate control relay and if any one those input is malfunctioning, and the compressor cuts off.

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Saumil S. Patel

Is your climate control rotery switch set to max when it cuts off?

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William
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1987 420 SEL - Like a fine wine only better with age

Thanks for the help Saumil.
I think I finaly nailed it down to the comp control relay but exactly what is causing it to turn of is still unknown.
I tryed to find your post on checking this out but was unable to do you think you could point me in the right direction.
Thanks Again
Chuck

Here is the post:

ac still not working after ac conversion 87 300SDL

Good-luck.

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Saumil S. Patel