My A/C on my wagon has been broken for about 3 years now. The latest diagnosis is that I have to replace the Climate Control Box. They said there is freon in the system.
Question: Any tips, ideas or other appreciated. It's proving difficult to find a guaranteed functioning Control Bx replacement. (Was told I need a Manual one.) So I want to be certain that this is a reliable diagnosis. Thanks

 

Exactly what does not work? Compressor does not come on? fan? Do you have MCC (manual controls) or ECC (you choose the temp and the system makes it hot or cold and there is an Auto position on the fan switch)?

 

Where are you located? Note in the US, MCCs are pretty rare, most 850s have the ECC . Do get a better diagnosis you will have to do some additional tests. Example, if the compressor doesn't come on, check the fuse first, then you can try jumpering the relay, next is to jumper the pressure sensors (you could have pressure in the system but a bad sensor). There should be both a low pressure sensor on the return pipe on the right fender (sorry I'd have to check exactly where the high pressure sensor is... too much pressure is not a common issue). Check YouTube for vids - I'm sure RobertDIY has done a few for HVAC issues on the 850s/

As to finding replacement parts, plenty on eBay and there's a lot of 850s in recycle yards. Car-part.com is a recycle yard search engine that covers North America so that's another good resource.

 

I have had Volvo's tor 20 years and have never had a working A/C. It was always been to much trouble to have maintained.

 

The only repair on an 850s AC that is troublesome in my view is when the evaporator leaks - that's about a 10-12 hour repair job since the dash needs to get completely disassembled. More common issues are a loss of refridgerant - could be the evaporator, old o-rings etc but a dye test is needed to confirm. A shop will evacuate the system, inject some dye with a charge and see if anything shows up. A new orifice tube and a receiver/dryer are typically installed as part of this service. The second common problem area is the AC clutch gap. As the clutch wears, the gap widens which causes the clutch to heat up and lose its grip so the AC will run for 5-10 minutes then cut out. The fix is to reshim the clutch to get the gap back in spec (the bread clip trick never worked for me...). Even if the compressor fails entirely, its not a difficult replace - its just that you'll need to get a proper recharge done similar to any car with an empty system. As to ECC issues, that's where you'd need to scan for codes but swapping out the control unit is a cheap fix since you can find used parts on eBay for like $50