Quote:
Originally Posted by joe_pau
My question is, when I press the AC switch, should the aux fan turn on immediately? And stay on as long as the AC switch is pressed?
Thanks
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No, not always depending on the high side pressure. there are 2 pressure switches on the air dryer. I know this has been mentioned above
One is the high pressure/low pressure cutoff. This switch only controls the compressor and will turn the compressor off if the pressure is too high, as well as if the Freon charge is low; it will not allow the compressor to turn on.
the 2nd switch is the low speed fan switch. (on my w126 for example), it turns on at 20bar(290psi); and enables the low speed fan. And it turns off at 15 bar (218psi). So your system high side pressure will need to be atleast 290psi for it to even enable. Which is a typical operating pressure after about 15-30sec of running. Then it will turn off once pressures drop below 218psi... (usualy when you are driving down the road on a avg temp day).
Not knowing the exact wiring setup on your w201, but it triggers a relay which passes thru a "preresistor" to give the electric fan slower speed.
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Just my MB's:
1990 420sel - Winter DD - 410,000km
1990 560sel - absolutely showroom mint - 360,000km!
