Temp gauge, '94 850

Discussion in 'Volvo 850' started by Ron, Aug 3, 2005.

  1. Ron

    Ron Guest

    Does the '94 850 have one of those odd 'middle of the dial' tpe temp
    gauges, like some of the 240s?

    My radiator cap cracked yesterday, and was spewing coolant for who
    knows how long, until the low water light came on...the gauge never
    moved from the middle. I also have noted on a hot day, with A/C on and
    pulling a grade, it does not move, and in the winter moves to the
    center fairly quickly.

    If it does have that weird circuitry, what is the fix to have some
    idea what the engine temp really is?


    Ron/Champ 6

    1963 8E5 Champ (Champ 6)
    1962 Lark Daytona Convertible On eBay now...(Boomerang)
    1995 VW Passat (Vanilla..yuk)
    1994 Volvo 850 (Tilley)
    1973 Volvo 1800 ES (Hyacinth Bucket)
     
    Ron, Aug 3, 2005
    #1
  2. Ron

    Mike F Guest

    Yes, it's like that, but if it doesn't show overheating, (assuming it's
    working as designed) then is really isn't. It's only to hide normal
    running fluctuations from you so you don't go running to the dealer
    every time you gauge goes up a millimetre higher than normal. Normally
    your car's cooling system has enough reserve capacity that it won't
    overheat in this situation.
    --
    Mike F.
    Thornhill (near Toronto), Ont.

    Replace tt with t (twice!) and remove parentheses to email me directly.
    (But I check the newsgroup more often than this email address.)
     
    Mike F, Aug 3, 2005
    #2
  3. Ron

    Ron Guest

    might as well have an idiot light, then... If you don't know that the
    fluctuations are normal, you shouldn't have a gauge nor a Volvo..maybe
    a Chevy or something mindless like that...

    ( off my soapbox now)

    Thanks, Mike

    Ron



    Ron/Champ 6

    1963 8E5 Champ (Champ 6)
    1962 Lark Daytona Convertible On eBay now...(Boomerang)
    1995 VW Passat (Vanilla..yuk)
    1994 Volvo 850 (Tilley)
    1973 Volvo 1800 ES (Hyacinth Bucket)
     
    Ron, Aug 4, 2005
    #3
  4. Ron

    Doug Warner Guest

    It's not a direct gauge. The temp sensor is connected to the combined
    instrument module, whose microprocessor moves the stepper motor
    pointer.

    There's a test mode (in the 94's) to see of the pointers and odometer
    are working. There's also a fault code readout to see if the sensor
    is working.

    Find the underhood test connectors and plug the wire into hole A7.
    Turn the ignition on.

    Fault codes:

    1. Press the button once, briefly (About 1/4 second)
    2. Watch the LED and count the groups of blinks. such as 1-2-2. When
    it stops, press the button again, keep doing this until the first code
    repeats.

    The two temperature sensor faults are: 1-2-1 and 1-2-2.


    Function test:
    1. Turn ignition off and on again to reset test mode 1, and then press
    the button 3 times.

    2. Look at the instrument panel for the following indications:
    Fuel gauge: Half full.
    Speedometer: Vertical.
    Tach: Vertical.
    Temp: Edge of the red mark.
    Odometer: Advances 5 tenths.

    If the temp pointer remains at midpoint, then it's the instrument pod
    ($$$$)

    If you had a new Volvo, the status would be impossible to obtain
    without a $50.00 visit to the dealer. This is why I'm not considering
    a new VOlvo to replace my 94.

    BTW: The temp sensor is also used by the engine management computer,
    and it it wasn't working, you'd probably have a check engine condition
    by this time.
    ..

    To reply, please remove one letter from each side of "@"
    Spammers are VERMIN. Please kill them all.
     
    Doug Warner, Aug 5, 2005
    #4
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