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Spring cleaning 900

posted by  someone claiming to be hillbilly on  Thu Mar 31 17:21 CST 2005 [RELATED]

Today I was changing the oil on my wife's 92 940 and thought that I'd try the AC and make sure that everything is OK. I pressed the AC button with the engine idling and the blower on low, waited a minute and nothing happened. First thing I did was un-plug the pressure switch on the accumulator and check continunity... checks OK so I assume that I have gas in the system. Next I jumpered the clutch on the Compressor and it engaged and ran fine, cold air out of the vent (50F), and sounded perfect. No juice to the Compressor clutch, where is the problem? I'm a old 240 man and I don't have a wiring schematic for this 940. Thanks in advance
steve








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    Spring cleaning 900

    posted by  miracleman49 on  Mon Apr 18 06:52 CST 2005
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    last visit: Wed Apr 6 15:53 CST 2011
    [RELATED]

    Hillbilly,

    concur with Spook and others, it is your temp control unit. I own 2 1995 940s, the AC control unit on the sedan went bad at 135k miles; the wagon ac control unit went bad a few weeks later at 129k miles. Planned obsolesence?

    Bought used (but working) replacements on Ebay, less than $50 inclulding shipping.

    good luck








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    Spring cleaning 900

    posted by  someone claiming to be Christopher Stipp on  Mon Apr 18 05:39 CST 2005 [RELATED]

    What was the outside temp? Doesn't the A/C ony work when the outside temp is above 47F? Of course one can force the A/C via the Defroster.








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    Spring cleaning 900

    posted by  tvpierce on  Fri Apr 1 04:13 CST 2005
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    last visit: Tue Apr 8 06:40 CST 2014
    [RELATED]

    This may seem rediculously obvious... but I bring it up because you mentioned you "pressed the AC button".

    You realize that the button is an "A/C Off" button. So when the button is depressed, the A/C is OFF. When the button is out, the A/C is ON.

    Just thought it was worth mentioning since it's backwards from every other auto manufacturer in the civilized world.

    Jeff Pierce
    --
    '93 945 Turbo ( one kickass family car ! ), '92 Mercedes 190E (my daily driver), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece -- sold to a loving home), '85 Jeep CJ-7 w/ Fisher plow








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      Spring cleaning 900

      posted by  someone claiming to be sredwine on  Fri Apr 1 06:14 CST 2005 [RELATED]

      Just wanted to follow up on the AC switch-on my 94 940T and my wife's V90,it operates "normally"-depress switch (which lights) to turn 'on' A/C.Volvo must have finally joined the rest of the world!








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      Spring cleaning 900

      posted by  someone claiming to be hillbilly on  Fri Apr 1 04:28 CST 2005 [RELATED]

      Thanks Typierce for the response. Yes, I'm familiar with the on-off button for the AC. My wife drove it all of the first winter with the AC on. She thought that she had a problem with her AC when it wouldn't work when she finally turned it "on" last summer. It is odd.
      steve








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        Spring cleaning 900

        posted by  someone claiming to be javalion on  Fri Apr 1 10:53 CST 2005 [RELATED]

        Ha, AC on all winter. (Similar experience in my 1993 trying to trouble shoot it.) They made the switch from unconventional to conventional in the 1994 model. The unit Spook speaks of is the unit attached to the on-off button in the dash.








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    Spring cleaning 900

    posted by  spook on  Fri Apr 1 01:28 CST 2005
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    last visit: Fri Oct 24 08:06 CST 2014
    [RELATED]

    Dear Steve,

    Good a.m. and may this find you well. The problem is almost certainly in the control unit. Specifically, there's a relay - a switch - which is activated by the A/C button. As this relay handles a lot of current, over time the solder joints can deteriorate (oxidize). A micro-crack in a solder joint can stop the flow of power. Chances are, you'll not be able to find the actual crack, becaus it is too small.

    The solution: open the control unit, and re-flow the solder, where each of the relay's four mounting pins enters the circuit board. It is also worthwhile, to re-flow the solder on the 14 or 16 pins of the main connector.

    This should put every back into sound working order. See the FAQs - under FEATURES, above - for the procedures. Post back, with any further questions.

    Hope this helps.

    Yours faithfully,

    spook








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      Spring cleaning 900

      posted by  someone claiming to be hillbilly on  Fri Apr 1 04:30 CST 2005 [RELATED]

      Thanks spook. This AC relay (control unit) that you speak of, where is it located?
      steve








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        Spring cleaning 900

        posted by  spook on  Fri Apr 1 11:54 CST 2005
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        last visit: Fri Oct 24 08:06 CST 2014
        [RELATED]

        Dear Steve,

        Good p.m. and hope this finds you well. Forgive me! I should have stated, that the A/C control is located in the front center console, above the radio. It has a fan speed selector on the left, a air-flow direction control knob in the middle, and an heat or heat/cool temp control on the right.

        Removing it is time consuming. If you search my posts, you'll find at least one, that deals with this process, in full detail.

        If you can't find such a post, I'll re-do it.

        Hope this helps.

        Yours faithfully,

        spook







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