In my 1995 855 wagon, the a/c cycles off after an while. If you turn it on full blast it stays on for a while and is too cold. If you turn in down or off, it then cycles off after varying amounts of time, say 2-5 minutes. If you leave it off for 5 minutes, then turn it on, it will work again for a few minutes.

Near the end of last summer I took it in and they put dye in the system and topped up the refrigerant. Last week I took it to the shop and spent about $500 to have the receiver/dryer replaced. Unfortunately, this did not fix the problem.

Now I am worried about repeated trips to the shop to slowly replace all the components for $1000's of dollars. Is there no way to positively determine where the problem is?

Any help appreciated.

When it cycles off how long does it stay off for?

The way you described the way it is working seems normal.The compressor will cycle off when the temp/pressure reaches a set limit.If it didn't kick off then it would freeze up.

Unless the copmpressor is staying off for like 15-20 minutes and not turning back on even though the switch for the A/C is on then the compressor will be bad.
But if it just cycles for a minute or so then that is normal.

Thanks for your swift reply.

It does not cycle back on by itself. Once it goes off, it stays off until you turn if off for a while, give it a rest, then turn it on again.

One shop I took it to recommended that I replace the sensors near the handles above the windows as they may be faulty. This does not make sense to me as it will not cycle off when just started - say on for 5 minutes - and the car is cold with the setting is on max cold). But if you put the temperture setting on a mid-range, it will automatically shut off as it should (but not turn back on when it should).

I think that the compressor has never been replaced. Apparenlty it is a bit noisy. Could it just be over heating and shut off? I had it turned on for highway driving last night (80 F) and it lasted 15 minutes.

Sounds like the compressor.
If you want to know for sure when it cuts off check for power at the compressor.If you have power then it is bad.
Or you can use a stick and CAREFULLY tap on the compressor clutch and see if it kicks back on if it does then it is bad.

Great, I will do... Er.. Just one detail. I have no idea where the compressor is or the clutch.
:(

But perhaps I may be able to find it.

The compressor is located at the bottom front of the engine.Going from the top there is the power steering pump then under that is the alternator and then the compressor.The clutch is the center part of the pulley.
Only tap on the center like you are trying to get it to spin.
You will see with the engine running the outside part of the pulley spins and the center isn't.

Thanks, I took a quick peek and found it. I will execute the test in the heat of day tomorrow. :)

Let me know how it goes.

Interesting. I left it on in the driveway for 30 minutes and tried different things and couldn't get it to fail. They also could not get it to fail in the shop.

The next time it fails on the road, I will try to pull over and tap the clutch.

I wonder why it fails on the road but not when stationairy? Perhaps the heat of the engine has something to do with it.

Let it get warm then take it around the block.In one area stand on the gas and make it rev it till almost redline and I will bet it will kick off!
When it is hot and you step on it the speed will kick the clutch out.

OK, I'll give it a whirl!

Ok let me know how it goes.