The Volvo shop "claim" they have found the cause of my air conditioning blues.

It is a defective "clutch" controlling the condensor. The clutch evidently cuts out during specific conditions, like an auto down shift from 4th to 3rd, and then will not come back on unless the system is shut down/off, and then restarted. Mechanic claims that leaving the fan motor on "high" (not auto) will by-pass the controller that operates the clutch.

I have made the decision to spend the bucks, but others may want to try the fan on "full speed" and forego the "auto" feature of the climate control.

The good news is, that the evaporator is fine, and they don't have to pull the dash/steering column. The bad news, of course, is the new part is about $250 and the labor is about $150 -- so a $400 invoice to correct. I'll bet it ends up higher, but it's not the $1500-$2,000 tab that I have heard an evaporator will cost to replace.

Will let you know if it is successful.

Joel S.
96 850

If you havent taken the car there for that, don't. I've never seen a bad compressor clutch but IT in itself is an OUTPUT device, it ONLY works when it receives voltage so it controls NOTHING. It has nothing to do with fan speed, modes or control unit functions. What you wrote above cannot be true and I'd get another opinion before wasting good money. Try going to a dealer with a good reputation or indy shop that knows 850 AC systems (like has ex-Volvo dealer techs working there).

Gary:

Well, whatever they did it "worked". The way they explained it to me (and I am not a mechanic at all)is that the problem is "rust" related, and partially for the pains of being a Clevelander.

There is a group of devices, the center of which is a "clutch" that is operating as a magnet. When the magnet (in the center) engages the outer machined disc (the clutch, I assume) it kicks the compressor on.

Evidently there is enough voltage to engage the "magnet" however, the magnet no longer has enough magnetism to continually engage the machined (or maybe cast) outer assembly. Particularly when the unit heats up and expands, the outer ring becomes more difficult to engage because the magnet just isn't as strong as it use to be. It was all covered with rust.

A couple of causes were sighted. One: is that the plastic lower airflow pan has come off my car several times. Usually, from parking over a high curb, which rips the thing off when I back up (I still haven't learned my lesson). Replacing it at $185 twice, just got ridiculous. The Volvo "dealer" did the work twice, and feels no remorse for its continuing to fall off (crumby part, and shoddy workmanship)-- nor does Volvo by the way (poor design).

Two: I have never parked my car indoors. It has been in the driveway for almost seven years. So, some rust is inevitable.

The bottom line is my A/C is working fine. And, I'm about $580 shorter in cash.

Joel
96 850

Thanx, Gary. That is what I did. The tech working the car "claims" he spent 12 years at a Volvo dealer.

Sorry to say that the work is already in progress. I will let you know the results.

If it doesn't fix it, I won't pay for it.

Joel