Volvo Repair: 95 850 turbo, turbo ac, freon

Question
AC has started cutting off for no reason.  I added freon and that did not help so I took to a shop and had them vacuum the system and refill.  Now it is worse.  The clutch comes on when the car has been setting.  It cools very good and you can switch on and off and the clutch chetches fine.  After driving a few minutes, it the clutch disengages.  Sometimes it will come back on.  Can I run a wire from the battery to the side of the Compressor the next time it stops to check if it will engage?

Thanks.

Rodger

Answer
Rodger, sounds like a bad pressure switch.  How much freon did they put in?  The 850 is very picky.  Anything more than 1.63 lbs will start acting funny.  Check to see the gap in the clutch.  If its too wide then it will also do what you are describing and the clutch would need to be reshimmed.  Roger