92 240 AC Stopped Working
 

Hey, all.

I've looked through a number of other posts on busted A/Cs and searched around some on the Web too and am still at a loss as to what's going on or even what I'm looking at under the hood.

First off, I'm unclear on how to tell whether or not the system's been converted from an R12 to an R134a. I'm attaching a picture of the accumulator hoping that'll help? Records show that the A/C was last recharged in 1999, so, guessing that'd have been R134a…I'm hoping.

Then, to the problem at hand, the A/C just stopped blowing cold air when switched on. Worked a month or so ago, now, not so much. Another thing I noticed, when it did work, a pretty loud squeaking would coincide with the A/C being turned on—squeaking would disappear when the switch was turned off but fan was still blowing. Now, no squeaking at all when the A/C switch is turned on and no difference in sound when the fans on vs. A/C switch thrown.

Likely'll just take it to our usual Volvo guy here in LA, but I'd like to have an idea on what's going on first and whether the system's been covered already or not.

Thanks in advance, all!

The gage service ports on 134A are quick connect,and R12 ports are threaded.Retrofitted,there would be a quick coupler adapter screwed onto the R12 fittings.This was a requirement with the switch from R12 to 134A so you could not inadvertently connect one type to the other. In your picture,it's difficult to tell with the cap on.
With the A/C turned on,does the compressor clutch engage,you should hear it click,and see the hub spin. If not,it could be a few different things,from low refrigerant charge,to a faulty,pressure switch,or faulty compressor clutch. If it short cycles,kicks on for a couple of seconds,then off again,it's likely low on refrigerant.You can use a test light to check for power at the compressor clutch. (engine off/key on -careful of spinning belts and pulleys )If no power,then check for power on the low pressure switch usually found near the accumulator.If there is power,then a jumper wire across the switch should turn on the compressor. If the compressor turns on,then the charge is low.Only jumper the switch for 30 seconds or so,since a leak also means oil loss,and the compressor could be damaged. Since the compressor also turns the power steering pump,I would assume the belt must be ok,or you would have hard steering. One last note, for those who charge their own systems with the Walmart type kits,PLEASE do not be tempted to use the sealant type refrigerant ! This stuff kills $4500 refrigerant recovery machines,and can kill you if breathed.Take your car to a professional if you are not sure.