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How to clean and reuse an ignition switch.

Discussion in 'Electronic Basics' started by Sam Nickaby, Oct 14, 2005.

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  1. Sam Nickaby

    Sam Nickaby Guest

    I have a 1988 Honda ignition switch that I have opened up. It's full of
    harden grease. I believe this is causing the car to stall when it loose
    momentary contact.

    What kind of solution should I use to clean the parts and what kind of
    grease or solution should I put back inside the ignition switch?

  2. Rich Grise

    Rich Grise Guest

    If you have the switch in your hand, with the key in it, so you can
    freely switch it back and forth at leisure, then any old solvent
    will do - 70% isopropyl alcohol springs to mind. If you splash a
    little isopropyl and it doesn't loosen the crud, soak it overnight.

    If that doesn't work, try increasingly aggressive solvents - mineral
    spirits (turpentine), benzene or toluene, MEK (but be extremely
    careful - it will attack the plastic), and as a last resort, acetone.
    If you're impatient, you could pay a seriously inflated price for "contact
    cleaner", which you could probably get at Radio Schlock or its equivalent.

    To lube it, get some dry graphite-based lubricant. The car parts store
    should have someting along those lines.

    Good Luck!
  3. redls1bird

    redls1bird Guest

    Being an automotive technician, im inclined to believe that it
    probably not the grease causing the car to stall out. Although th
    ignition switch very well could be worn out, replacing it would mos
    likely take care of your problem. Carb cleaner from a parts stor
    will easily disolve the grease. As for the new grease, it jus
    lubricates, doesnt have to have high heat resistance nor keep ou
    water so almost any kind will do as long as its not too thin and ma
    run out
  4. Sam Nickaby

    Sam Nickaby Guest

    I have the ignition (electrical) switch apart. I see some harden grease
    (dark substance won't come off by rubbing with a fingernail.) I am
    tempted to try aggressive solvents or sand off the dark stuff with a
    400 grit sandpaper. I do see some wear on the switch (about 1/4 of a
    mm) but not enough to throw it away even after 200k miles. Won't
    the new grease affect resistance? And if I go without any grease
    should the copper contact wear faster?
  5. Jasen Betts

    Jasen Betts Guest

    A new ignition switch unit is probably less expensive than having that
    one fail and run the starter while the engine is going and destroy the
    starter and demount the ring gear etc...

    this I learned the hard way...

  6. spudnuty

    spudnuty Guest

    Hardened grease is a common problem in equipment of this age. I'm
    accustomed to it happening in 3.5" floppy drives from the early '90s
    although it did happen to my mom's apple peeler. I would just clean it
    with an appropriate solvent (as above) and use a good switch grease and
    reassemble. Altho' the gunk you describe sounds different. Usually
    it's the consistancy of taffy. Sure the contacts or switch is not
  7. w_tom

    w_tom Guest

    The grease seals electrical contact points from exposure to
    air and corrosion. Any sparks made during break or make are
    quashed. It conducts heat created during such contacts. It
    must be a wide temperature material that does not harden in
    cold and flow in heat. Must be high temperature so that the
    spark does not cause combustion. Conventional grease is not
    acceptable. It must not react with the existing (previously
    installed) grease AND must not react with materials inside the
    switch. It must not be electrically conductive.

    Cannot tell you what will meet those requirements since that
    requires proprietary information from the manufacturer. But
    you could test some automotive bearing lithium based grease
    that are also high temperature materials. Before using, first
    measure its electrical conductivity.

    You are doing this to learn - clearly not to save money or
    to make the vehicle more reliable. Those other objectives
    means buying a switch from the dealer.

    Most people don't realize how complex a switch really is.
    Worse, most simply clean the grease off of switch contacts and
    off of electrical connectors. They want to make things clean
    - thereby creating the computer, sensor, or other failures
    that occur later. IOW they don't learn the whys before making
    assumptions. You are doing this only to learn the whys.
  8. Just out of curiosity why acetone as the last resort? MEK seems allot
    more hazardous, is it not?
    I don't think I'd lube the switch contact area with graphite, maybe
    dielectric grease to keep out moisture and prevent arcing. Graphite is
    good for lubing the pins and keyway though.
  9. Rich Grise

    Rich Grise Guest

    No, actually, MEK (methyl ethyl ketone, C2H5COCH3) is a bigger molecule
    than acetone, which is dimethyl ketone, CH3COCH3 - it absorbs into your
    skin slower, it has a higher flash point and lower vapor pressure - I
    could look up the MSDS, but I'm way too lazy. :) (looking up the formula
    was trivial. :) )
    Yes - this is what I meant, and I apparently wasn't clear. Thanks for
    the clarification.

    But others have suggested some Lithium or Moly grease on the contacts,
    which actually sounds like a rather good idea. It will keep them from
    corroding, and the physical movement of the contacts will ensure a
    good electrical contact, by the wiping action.

  10. nothanks

    nothanks Guest

    Last time I priced an ignition switch for my Volkswagen it was on the
    order of $10. The biggest PITA was putting it back in. I can't possibly
    imagine why you would want to service a part that costs so little and was
    never designed to be serviced.

    If the ignition switch fails again you could wind up stranded or damage
    the starter and/or flywheel. The cost of either of these events will be
    *WAY* greater than the cost of a new switch, and you'll be buying a new
    switch then, not to mention going through the labor of removal and
    installation of the switch a second time.

    But thats just me...
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