A friend has this 94 850 with AC not working. The compressor clutch does not engage when the AC is turned on. He brought it to the dealer for AC diagnosis. Came back with the verdict as follows:

"C/S A/C not blowing cold -- Fault traced to an internal electrical fault in the "ignition control module". The part's # is P/N 9146296"

The parts cost $800. Labor is another $200 and change. My guess is the stealer simply plugged in to the data link and read it. Would like a second opinion. Thanks.

Following advice of several of you, I had the friend bought two cans of R-134a and helped him recharge it in my driveway. As soon as I had the first can in, a hissing sound started. Tracing the source and wet spot, I found the receiver was leaking.

Now could you find a more irresponsible dealership? Why would they diagnose the problem as needing a new ignition control module, to the tune of $800 plus labor?

Wife complained to me last night that our 93 940 wagon has a dead AC for two seasons and yet I put friend's 850 AC problem first. The 940 also has full r134 but no AC. Clutch engages too.

I'm having the same sort of problem, as are a few other people on "another Volvo board". AC cuts out on WOT, (wide-open throttle), but then it won't re-engage.

R134 level is FINE, and NO leaks!

With my car and the other cars, dealer and non-dealer tech opinions include: cabin temp sensor, climate control module, AC compressor, compressor clutch and clutch gap, various sensors including the compressor temp sensor....

I suppose ONE of these things should fix the problem, 'cause there isn't much else left!

I'm baffled at this point.

-BTC

I would have it recharged first. Not at a dealer.My wife's( I sold mine) 97 turbo..... Went well for two years. The dealers love to have a new complete customer. Just a thought. That is why I don't drive a Volvo anymore (One of the reasons.)

It's probably a leak and it's probably the evaporator and it's probably going to cost alot more than $800. From what others have said count on paying roughly twice this at a Volvo dealer to get it fixed. The whole dashboard has to be removed. You can shop around but not too many have been able to get the job done well for under $1000.

How to ascertain if the evaporator leaks? One obviously does not want to tear the dash apart to get to it and finds the evaporator is not the culprit. Since the compressor does not engage, it won't take any charge.

Make sure the can of r134a is full by shaking it. I have bought cans that were empty.
I also had to jump the low pressure switch to get the compressor to start and suck the can dry. Took 2 cans.

Klaus
--
98 V70Rawd(108Kmi), 95 854T(88K mi), 75 164E(173K mi)

If the air conditioner is empty of refrigerant this may be why the compressor does not run. There is a low pressure cutout switch in the lines from the evaporator. Remove the plug from this switch and place a jumper wire across it for a just couple of seconds to see if this is why the compressor does not run. If compressor runs with the jumper across the plug then recharge the system. If not then you have something else wrong. If the compressor does run, fit a can of R134A with an appropriate hose (can, tapper, hose, and gauge can be bought in a kit) to the low pressure fitting. Tap the can to let the R134A flow in. In my case with the system empty the refrigerant flowed sufficiently through the system to build a little pressure and then the compressor started by itself. Some people said they had to jumper the plug for a few seconds to get the process started, but I did not.

If the system is empty it may have a slow or a serious leak. I used the duPont "Suva" brand of R134A which has a dye in it. You can find a leak with a blacklight. The dye is very bright under the light - if you do this in the evening you would not miss a leak. However the evaporator is often the source of the leak according to many people's posts. That is hard to deal with because it is buried in the heating plenum. You would probably have to remove the heater fan to get close enough to see if that is the leak source. If so replacing it is a big job. With a slow leak you might be able to just recharge from time to time.