Hi,
I've been having strange problems (white smoke from vents, erratic cooling) with the air cond. on my 940GLE and have just discovered that some previous numbskull deliberately shorted out the wiring to the Pressure switch!. I removed the short and now the compressor is cycling on and off rapidly. I removed the switch from the accumulator onto the bench, tested it with an ohm meter and it is 'open'. I rigged up a test jig using an air compressor and the switch does not 'close' until the pressure reaches 41psi.I did a google on the switch (1259519) and eventually ascertained that it should be normally 'closed', 'open' at 21psi and 'close' again at 41psi. Has anyone any experience of the switch and can confirm that it should be normally 'closed' on the bench, ie at zero pressure?

Thanks :)