Ok, wife called 5pm and said the a/c isnt working but it was fine this morning. Once the car is home I checked the fuse, 2 relays behind glove box, all look good so I hook up the low side gauge and I have static pressure. Start car, turn a/c on and compressor wont kick in..jumper out the low pressure switch and compressor kicks in and ive got about 35 psi (seems ok). Reconnect lower pressure switch and no compressor engagement. I'll mess with it later..
Next morning, everything works fine again...lunchtime, everythings still working fine, 5pm again and no a/c !!! Any ideas ?

To follow things up, I got the new LPCO switch Sat morning. Popped the hood, Unscrewed the old one, when putting the new switch on I heard a "click". I put my DMM and had full continuity ! Connected the wiring & started the car, turned A/C on & everything works. Took me about 5 mins & $54 to get it working ! Thanks Again KlausC !!

Clutch seems fine, A/C still not working.
System has correct pressure.
Low Pressure Cut Out (LPCO) switch bad ?
How do you check them ? Ohm/Continuity ?
Digital meter shows nothing when it was probed.

Can I unscrew it without it bursting thru the hood ?
Or, is there a schrader valve under it ?

Anyone care to pull the clip connector on a working system & put a continuity check on the LPCO for me ?

I just did a search on "pressostat", the low pressure switch:

"I just replaced the low pressure switch (Volvo calls it a pressostat) on my 97 850. It takes less than 5 min. The line where the swith mounts has a built in schrader valve so when you unscrew the switch, the valve closes automatically & you will not lose any freon. Screw the new one on, reconnect the electrical plug & you are ready to go."

The pressostat is around $50 at the dealer, but most AC shops should carry the same item.

To verify the problem is the pressostat, unplug the wires going to it and using a wire or paperclip, connect it to the + and - side of the plug. The compressor should start up and give you cold air.

Klaus


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Just driving a 1998 V70R :)

Thanks KlausC, great search...now why didnt I think of that ? Ive used it before so I guess I just got too fustrated this time and yelled help !
Hope I can return the favor someday !

Either the clutch gap is too large at the compressor or the pressostat switch is broken.

Klaus
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Just driving a 1998 V70R :)