Volvo Relays

Discussion in 'General Motoring' started by Guest, Aug 5, 2005.

  1. Guest

    Guest Guest

    Mine is a 1991 Station Wagon, 740. 140K miles. I had a no-start several
    days ago but it has started OK since. I suspected the fuel pump relay so I
    pulled it and put it back in (presumably cleaning the contacts in the
    process). The car has been fine since then. But I am worried about certain
    relays. In the front row, the K relay (central locking?) is too hot to
    touch; the J relay (window?) is quite hot (but not as hot as K), and the
    fuel pump relay is quite warm. In Brickboard I have seen two views; "Volvo
    relays are always hot", the other "A hot relay is a bad relay".

    Does anyone have any views on this (the others are are only very slightly
    warm or only ambient temperature)?

    Thanks,

    John
     
    Guest, Aug 5, 2005
    #1
  2. Guest

    jg Guest

    Dunno what is normal but I don't like hot electricals. I saw a suggestion to
    drill some small holes in the casing... while it's off. I followed the
    suggestion with a new fuel pump relay 8 months ago but who knows if it will
    help? They did say 7 years was about normal lifespan for those (1980 265),
    which doesn't sound very good - seems something shortens its life.
     
    jg, Aug 6, 2005
    #2
  3. Guest

    James Sweet Guest


    They're made by Bosch and have circuit boards inside. When they get old the
    solder joints at the connector pins tend to crack and result in an
    intermittant connection. If you know how to solder or know someone who does,
    or feel like spending $15 on equipment and a few minutes practicing, it's
    fairly easy to pop the cover off and resolder them.
     
    James Sweet, Aug 6, 2005
    #3
  4. Guest

    James Sweet Guest

    If it's getting more than just a little warm, you've got a bad connection or
    excessive load. I failing fuel pump will draw too much power and melt the
    relay and connector. Also once the connector gets hot it oxidizes which
    causes resistance and then more heat. I suggest checking the current draw of
    the fuel pump, if it's pulling more than 10A it's probably worn out.
     
    James Sweet, Aug 6, 2005
    #4
  5. Guest

    Guest Guest

    The car is a l991 and it did have fuel problems in 2000. The fuel pump was
    then replaced and a new relay installed (date code 1999, made in Hungary).

    I will replace the relays one at a time, starting at the hottest and see
    what happens.

    Thanks.
     
    Guest, Aug 6, 2005
    #5
  6. Guest

    Boris Mohar Guest

    This is what it can look like: http://www.viatrack.ca/Misc/badcon2.jpg


    Regards,

    Boris Mohar

    Got Knock? - see:
    Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca
     
    Boris Mohar, Aug 6, 2005
    #6
  7. Guest

    Randy G. Guest

    Here's a link on an article I wrote, aimed at beginners, on how to
    solder:
    http://w6rec.com/duane/bmw/solder/


    __ __
    Randy & \ \/ /alerie's
    \__/olvos
    '90 245 Estate - '93 965 Estate
    "Shelby" & "Kate"
     
    Randy G., Aug 6, 2005
    #7
  8. Guest

    Guest Guest

    Thanks, everyone, for great comments and suggestions. I'll do the
    resoldering first (I'm well experienced) and will go from there.

    John
     
    Guest, Aug 6, 2005
    #8
  9. what a brillant shot thank you

     
    John Robertson, Sep 6, 2005
    #9
  10. Guest

    Boris Mohar Guest

    It was taken with a digital camera held manually against the eyepiece of a
    microscope. Microscope projects image at infinity so there is no trouble
    with focusing. Anyone can do it.


    Regards,

    Boris Mohar

    Got Knock? - see:
    Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca
     
    Boris Mohar, Sep 6, 2005
    #10
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