so i have a 95 850 turbo and the ac does not blow cold air, ever. the front end of the car had some damage when i bought it, and what i am fairly sure(from reading on here/ wiring diagrams), is the a/c high pressure sensor(switch?), is broken in half. so i clearly need to replace this, it seems to be about 100 new, and am trying to find a used one.

anyway, it isnt clear to me from reading on here about ac problems if this being broken would shut down the ac? also it seems like i will be opening up the system to replace it and would therefore need to recharge it? so if thats the case i guess i would like to check out any other possible problem causes before having to recharge the freon multiple times.

i was slacking on trying to do anything about this for awhile, but now i live in tucson and its too hot to not have AC.


thank you

 

To answer one of your questions, I believe the AC will NOT work or even attempt to turn on if it is reading an abnormal pressure.

 

I just did a quick search but a new one at autozone is $66.

A/C Switch | 1995 Volvo 850 5 Cylinders 5 2.3L Turbo DOHC | AutoZone.com

The low pressure switch is the one saving the compressor from running low and failing to get lubricated and burning up.

The high pressure switch should be normally closed and open up when the pressure builds past a safe level. I'm guessing that would be in the high 500+ psi range. You should be able to jump the wires together to test the system to see if the clutch will kick in. If it does it indicates you do have at least the minimum amount of freon to operate and from there you would want to get a new (used) high pressure switch and hook up a gauge to the low side to see where you are for low side pressure.

If the system doesn't kick in when you jump the high pressure switch it would usually indicate you likely have a leak and are to low on freon. Usually you need to get over 20 psi for the low pressure switch to engage the compressor.

 

thank you for the info and for looking up the part. im gonna try the junkyard place tomorow. then search the webs a bit better probably.


would you know which 2 of the 3 wires need to be jumped together? i will try looking at the wiring diagrams when i get home to see if i can figure it out.

 

Try these:

http://www.matthewsvolvosite.com/for...hp?f=1&t=39041

http://www.matthewsvolvosite.com/for...hp?f=1&t=27648

Another place to try if you chose to get the switch new would be rockauto dot com.

 

got a/c working. thanks for the help.

better than the junk yard, a friend has the same car and they are getting rid of it so i was able to just take the high pressure sensor off it. didnt work right away, so jumped the low pressure switch and i could hear it come on for a second. got some freon, unfortunately too much, and now i have a/c again