I'm trying to sort our the A/C system in my son's 88 190E 2.3. Replacing the condenser took car of the leaks. The system now holds pressure. While at it, I installed the fittings to convert the system to 134. Now, the problem starts. When you activate the A/C, the compressor clutch will kick in and the system cools very nicely............for about a minute! Then the compressor clutch disengages. Since the system cools and there are no unusual noises from the compressor, I am assuming that the compressor is fine. But, whatever controls the clutch is de-energizing it.

I have tried jumping across the low pressure cutout switch installed on the dryer, but that makes no difference in operation.

Can someone provide me with information on the items that control the A/C clutch on this car, and WHERE each item is located. I know that there has to be a hidden sensor somewhere that I am overlooking!

If I could understand the systems that control the clutch and knew where the components were located, I should be able to fix the thing! Unfortunately, the Haynes manual is totally lacking when it comes to A/C systems.

Thanks in advance.