I was wondering what came of this post? I too am having a similar problem. The compressor keeps cycling between 45 and 20. So I assumed I had enough freon. Should I add more? I was afraid of over-charging. I get nothing but warm air out of the a/c. Any other suggestions? Thanks in advance.

 

Same here.... compressor not kicking on since i bought car a year ago (purchased car a/c nonop). checked pressure with 134 recharge kit, low side pressure very low (<5 psi, but was some pressure - so no leak i expect). Added freon, pressures coming up, compressor cycling on/off every 3-5 seconds as pressure builds into the red zone. at some point between cycling, pressure pegs the psi needle (i think the gage on the recharge kit maxes at like 300psi), i disconnect and step back a few feet expecting the dayam thing to blow, feeling lucky that 134 can didn't already blow my hand off! Hmmmm.... seems something appears clogged....ya think? Could this be the oriface tube??? And where the he|| is that durn thing? If I take the car to Midas or someplace to have em flush the system, would i need to change the oriface tube???? Dryer??? Should I trust them to do? Advice? TIA!!

 

The evaporator in the system is almost certainly the culprit here, it's a matter of corrosion, the unit corrodes behind the plastic foam at the sides, there is a replacement kit (with corrosion protection and air filter) for this as it is very common for the 850 model but not the V70 that got the new enhanced evaporator.

The unit is placed under the dashboard so its a very expensive job at the shops, in sweden it cost me 12,000SEK (approx $1900) to change it in my Volvo 850R -96.

Another problem is the abs unit on 850/V70 up to 1999 reporting intermittent abs sensor malfunction (usually right rear) or pump motor malfunction, it's the unit that is faulty not the sensor.