Re S70 A/C recalitrantness- solved- info of possible use- Mike F et al

Discussion in 'Volvo S70' started by Guest, Aug 4, 2004.

  1. Guest

    Guest Guest

    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..
     
    Guest, Aug 4, 2004
    #1
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