W126 AC Compressor question?
 

I got scared and worried at one point but until today.....The AC compressor I noticed stopped working when I hit the defrost or even the AC controls. I thought oh no......more $$$ for this!! Then as I was putting some papers into the pouch of the manual, I took a quick glance of the climate control instructions and it sain on the bottom, that pressing the defrost or the other 2 AC buttons, the refregerent compressor will not actuate in temps below +2 or 36F. Phewwwwwww!:rolleyes: I was releived, because it was not over those temps over here in ages!!

But my question is.....on other cars the AC can turn on whenever you want it to...why not the MB?

so nobody knows?

The compressor doesn't come on in other cars. Most A/C systems have a "cycling switch" which cycles the compressor off when the pressure drops to 35psi. A/C refrigerant has a pressure/temperature relationship and at 35psi it is around 35 degrees ferenhight. It doesn't really have anything to do with the car but rather the system.

If the temperature in your area is so cold, why do you want A/C for anyway?

hope this helps.

No not that I want the AC on...:rolleyes: but I heard its good for it to work once in a while cause it prevents leaks and keeps the system "healthy" unless this system does something by itself to do that, I dont know.

The A/C system operates all the time except "ec" in a climate control system.

Another dumb question here.......
 

.....while the topic is still fresh. What type of refrigerant is/was used in the 126's, specifically a '91 300 SE ? (fingers crossed for 134) Mine isn't working but was last year, I've known this car and the previous owner for about 3 years now.

Well it was quite warm out today so it was a good chance now to see if the AC worked and, sure enough when I hit the button the system fired up!:D The manual is correct as it only works above 36F.