Hello. I am going to attempt to explain what is going on with our 85 240 wagon - my husband is not here right now and he is much more car knowledgable than I am, but thought I would give it a try.
About 6 months ago we had the air compressor changed in our 240 wagon as it was bad and the car was not drivable. We also had the air conditioning converted at the same time. The car now has quite a loud chirping sound whenever the air conditioner is on. About a month ago I noticed this only when the conditioner knob was in the red or when the car was started with the air conditioner turned on. I also notice that the car gives one chirp whenever it starts up. We havent been really using the air conditioner much until recently, so didnt notice this before.
My husband suggested it may be either a faulty clutch or something with the belt. Could it be that the compressor they gave us is bad, used, etc? Would you take the car back to the shop and ask that they fix it, or not bother since it's been 6 months now.
Does anyone have any suggestions on what this might be?

Thanks much for taking the time to read this.

Jen