The A/C on my '97 S90 works fine and then kicks off after about 20 min. I figured it was a bad compressor $$$ but have recently learned it could be something else. This particular compressor has a thermal switch on the back of it that will kick off the compressor if it gets hot(ie low freon) Anyway I have learned that Volvo has had problems with these switches and has had their service techs bypass this switch. (the new compressors don't have this switch) Finally to my question. Has anyone heard of this and if so how difficult is it to bypass the switch. Thanks!

 

Yes I have heard of it. Most of the time they think that is the problem but it isn't.
It is located on the back of the compressor. It is plugged inline with the power wire for the compressor. Unplug it and connect the power wire straight to the compressor. No modifications needed. Just plug and play.

 

Thanks Tech, got my fingers crossed on this one. I got an estimate to replace the compressor and dryer(comp. warranty requires this) and recharge system. $1200 Does that sound in the ball park?

 

That is somewhat close. The compressor is Like $500.00 for a NEW one and a Rebuilt one should be like $350.00.
Then I think it is like 4 to 5 hours labor.

 

This sounds like what is happening with my '94 960. Only had the car three weeks and it's been in the shop for one of those weeks having the heater core replaced ($860). Is there any reason to NOT unplug this relay, if my car has it ? I put in a can of R134a yesterday. Only about half of it went in. The can wasn't cold and wasn't getting condensation on it so I took it off after about 15 minutes and discarded the rest.

When I start the car the a/c blows ice cold. Within ten minutes it's blowing hot air. I had theorized that the heat is on, even though I have the temperature dialed to 72 or lower. Is there anything else I should do or check ?

 

When the A/C stops blowing cold is the compressor still running?

 

Weren't there more posts in this string ? Can't see any past the first page, so maybe not. Anyway, the problem persists. After bypassing the switch/thermostat/relay or whatever that little black box was that was in the power wire, nothing is any different. I've called everyone in the area and have found no Volvo specialist in "upstate South Carolina". Any suggestions ? ... thanks for any you can offer and for the previous efforts

 

I am having the same problem with a 97 960. I spent most of the summer in Flagstaff Arizona where AC is not needed too much. This week I am in Phoenix, after driving for about 20 mins or around that the AC just starts blowing warm air. Then if I park in the shade, put the windows down a little and wait a few minutes everying seems to work fine again. If I were to bring this car to a shop or volvo dealer how much do you think it would cost to be fixed?

 

My advice is to not spend money on it. The previous owner of my car was good enough to pass along his service receipts and he started having this problem two years and 20,000 miles ago. He had every component in the climate control system replaced chasing it and spent over $4,000 before he gave up and traded the car in. I've had it diagnosed and basically the mechanic was honest enough to say he couldn't find anything wrong and didn't charge me for looking it over. Unless I find a real specialist who can convince me he knows how to fix this I'm regarding it as a flaw in the design and we're driving my wife's Honda until the temperatures go below 90 again.