Hi, I have a 2002 V70. AC not working as advertised. I can get the clutch to engage and the car cools down nicely by jumpering the relay, and also by applying 12v to the clutch wire at the compressor. I know for sure that when jumpering the relay, the compressor is always on - forgot to check the other way but would assume this to also be the case. I've been doing some looking around online and with respect to pressure switches and the only thing I came up with was about a thermal cutout switch on the compressor. I went to look for it and don't see anything.

Does anyone have any AC system diagrams and or principles of operation? - Having this would help me immensely. Any other suggestions are greatly appreciated also!

Thanks...

 

All A/C systems have a pressure switch, so that the system doesn't operate without r134. Have you just tried recharging it first, this would be the first thing to eliminate as a problem.

 

Good point. I did actually try adding some freon before jumping the relay but the compressor never kicked on. That's always worked before which is what threw me off initially. I'll put my guages on the system to see what those are reading before I do anything else. Also - I wanted to share this cool web site that I just ran across. It's for vehicle AC systems; it's definitely worth saving in your bookmarks. IDQ - Auto A/C Products & Sealing Solutions