94 850 GLT - A/C High Pressure Switch test

[fle]

Hi list,
I would like to have advices on the possible failure on my HPS, before buying this costly part. This is the story :

I am in the process of fixing my A/C that I didn't used for years.
Before testing the system for leaks, I am checking the electrical part of it.
I noticed that my compressor solenoid get energezide only if bypassing the low pressure switch (which is "normal", the circuit being probably empty by now) and the high pressure switch also. This is weird to me, as if there is no pressure in the circuit, this normally closed switch should be closed.

So here are my questions :
1- can somebody confirm that it is a normally closed circuit ( unless there is a too high pressure in which case the switch opens) ? in which case it would mean mine needs replacement.
2- can someone confirm that this switch can be changed with the circuit under pressure, as there seems to be a schraeder valve ? in which case I could change it by myself even after the leakage test.

The switch p/n is 9132754. I looked at the wiring from a german workshop manual for question #1, and at fcpeuro drawings for question #2

Thank you for your help.

[fle]

the answer is here :
http://volvoforums.com/forum/volvo-850- ... tch-79119/

[msb3000]

I found an easy way to eliminate the high pressure switch. The clutch relay already has power and works off of being grounded by the computer. Take the ground side of the relay and ground it to the battery or wherever. Then take the small power wire and put it loop with the low pressure switch. AC will cycle and cut off when low on freon .