Hi all,
I posted last week of my 97 S70's a/c packing up having been working fine until i messed with the connector on the low pressure(?) switch infront of the ECU box.
Anyways, its now working again. I checked the lowpressure switch connector & contacts again, all the climate control fuses (2 in the central fuse box) and the a/c relay in the engine fuse box. These were all fine as I'd expected, yet still the compressor clutch would not pull in despite the a/c light being on in the cabin.
Testing the relay on the bench with 12v, it clicked and there was electrical continuity across the switch. I then jumpered the a/c relay socket (helpfully a pictorial is printed on the relay itself) and the clutch pulled in. With the engine running, and the socket jumpered I got cold air, however the engine idle speed flagged as the compressor engaged, and the rad fan was not powering up- pointing to the ECU being at fault.
Disconnected the battery -ve lead for 10mins as my next plan of attack. Reconnected and fired up the engine. Pressed the a/c button and.................the compressor engaged, shortly followed by the fan!
So it seems as though the ECU had logged a fault with the low pressure circuit (open circuit caused by me) and disabled the a/c. This was still the case a week and ~ 50 start-ups later, so it did not reset after so many key on / offs.
This may be of help to anyone who's a/c suddenly stops working without warning and thinks they may have suddenly sprung a refidgerant leak...
Tim..