Intermittent Windscreen Wipers

Discussion in 'How To' started by mikedjames, May 23, 2022.

  1. Thusly. Saves a lot of faff.

    a newy2 intermittent switch 6s.jpg
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  2. scrooge95

    scrooge95 Moderator and piggy bank keeper

    Wiring defeats me.
    I'm sure you're right though about my extra stalk position being contactless, that would just be too perfect if it was all there waiting.
    I think Mike's idea of ditching the fast setting and having intermittent instead is okay, I never use fast anyway. But it's all above my head!
  3. Ditch fast and hope you never get caught in a rainstorm ;)
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  4. mikedjames

    mikedjames Supporter

    Mine had no real difference in speed, because of lower torque in fast. And now the relay- powered slow is faster than the old version.
  5. Need a new motor, mate.
  6. mikedjames

    mikedjames Supporter

    No, it was the switch.
    I stripped the motor down and cleaned it up at TE, re-lubricated it, no difference, wipers would stall out on a dry screen.
    Stripped down switch, wipers now move fairly fast on a dry screen.
    Replaced switch with relay, wipers still move fast.
    Switch contacts
    Switch wiper

    And then it managed to get one of the arms to slip on the spindle.
    Last edited: May 29, 2022
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  7. Has Clem got the big chunky earlier stalks, or the slim later ones?
  8. scrooge95

    scrooge95 Moderator and piggy bank keeper

    The lovely thin stalk with the flat paddle on the end, '72 to '74 style. Beautiful.

    (Excuse lack of door card, I am ‘refurbishing’ !)
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  9. mikedjames

    mikedjames Supporter

    Working on a dry windscreen..
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  10. mikedjames

    mikedjames Supporter

    Aagh. I was looking at my pictures and I have just realised the "useless" extra switch position brings the plastic block inside the switch right against the side of the switch mechanism... drill a small hole, fit a tiny switch e.g. one of those PCB mounted tact switches, connect that to the I terminal on the relay, then down can be intermittent ...
    Might even be able to fit a proper microswitch..
  11. mikedjames

    mikedjames Supporter

    Not long ago, I was able to get hold of a wiper switch that did not need an internal cable tie to make it stay in one piece, so I was able to use the old switch to mock up prototypes of a secondary switch assembly for the washer switch and another switch for the intermittent wipe, that bolts on in place of the stock water valve under the wiper switch.

    I had sat there looking at the switch which is wired to provide either 12 volt power to fast, slow motor windings, or connect the stop switch on the gearbox to the motor slow winding for parking.
    When the endstop plastic block is missing in the switch, there are two identical parking positions on the two detents pulled towards the drivers seat.

    But what I noticed was that when you pulled the switch right down, the internals of the switch covered over the hole where the block would have fitted. And in the first parking position, it did not cover the hole.

    So I designed a tiny cam and tried it ..


    That slides into the hole and is stopped by some ledges inside the hole. Shown in place at the end of the blue arrow..
    The cam pops down by 1mm when the switch mechanism hits it, and pushes it down rather than snapping it off.

    Then I needed a frame to hold some microswitches ..
    So far I went through about 20 prototype shapes, gradually evolving the form that I finally dared try on the bus.. The constraints are the curved shell covering the switch, and the C shaped pieces that clamp it onto the steering column. So basically the thing I designed is almost as large as it can be.

    This is quite weak, and has the problem that the fixing bolts for the microswitch on the right get in the way of a screwdriver going down to the fixing screw holes.

    But I got it all in place ..

    You have to be very careful not to let those brass threaded inserts drop inside the switch, or you have to take it apart and fit them again (preferably with a spot of glue to keep them in there.)
    Just after I took those pictures, they fell inside the switch. I should have carefully screwed some M3 bolts in there while handling the switch.


    The left hand microswitch goes to the T terminal on the 99 relay and the screen wash pump - I havent used a relay as the previous switch seemed to be OK for years.

    The right hand microswitch goes to the I terminal on the 99 relay.
    So now the wipers have four positions - starting at the top :
    • Fast
    • Slow
    • Off
    • Intermittent
    And pull to wipe.

    I am sure my little 3D printed frame can be improved as the base of the right hand microswitch is so weak. And the cam tends to get jammed in the hole sometimes .. I may have to print it a bit smaller to get it to fit better, but not so loose it tilts over and jams. Its all a balance , the end of the microswitch lever has to go exactly in the middle of the little cam or it tips over. .

    And ideally I would be able to fit the thing to the base of the wiper switch without leaning a screwdriver over at about 20 degrees to drive in the right hand fixing screw.

    Last edited: Jul 30, 2023
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  12. Belly

    Belly Button fluff

    If you have paddle style controls 72-74 maybe and want full functions inc electric wash wipe/interval from the switches look out for wash/wipe stalk 211-955-501-D.
    Not easy to find but worth it if you manage to...
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  13. mikedjames

    mikedjames Supporter

    Despite printing the thing in nylon, my nylon filament was damp and it was damaged by the boiling water in the printer nozzle, so I ended up printing it in PLA because on a cold day that is better. But of course in very hot weather, it sags. So I am going to try again in nylon with a very fine nozzle for the cam.

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