Installing an Acewell speedo/computer on an airhead --

Discussion in 'Airheads' started by bpeckm, Nov 23, 2009.

  1. craydds

    craydds Long timer

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    the blue wire from plug "b" (see Acewell diagram post #302) is the fuel wire; not needed so it was deleted. the gray wire is a nothing wire that went to nowhere so it was excised:
    [​IMG]
  2. craydds

    craydds Long timer

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    time to connect each wire:
    [​IMG]

    ace red to bmw green/black, and so on, until all are connected:
    [​IMG]

    say goodbye to the stock plug. sob.
    [​IMG]
  3. craydds

    craydds Long timer

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    Know YOUR bike's wiring. I like the BMW owner's manual schematic, seems to be the most accurate (see post #293 for a '75 R90S). Study bpeckm's wiring instructions! Read through this thread again, and again. Know your specific Acewell model wiring diagram. (see post #302 for a model 4454 diagram).
    [​IMG]
  4. craydds

    craydds Long timer

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    I bought a light to make a generator warning lamp; will connect this weekend. A few other connections to make, then it will be ready for testing and calibrations.
    [​IMG]
  5. Boxer Metal

    Boxer Metal Mad Scientist

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    Thanks for the drawing. What size resistor did you use?
  6. craydds

    craydds Long timer

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    Chris, I have not completed this install, yet. I got the resistor idea from another thread; I'll try to find that again. They posted a link to Motorrad, http://www.motoelekt.com/charging.htm, who sold a resistor ready made to wire into place. Motorrad still lists the resistor, but it is part of their Omega charging kit; I don't see the resistor listed as a separately available item. I am going to call them.
  7. craydds

    craydds Long timer

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  8. craydds

    craydds Long timer

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    I called Rick Jones at Motorrad and ordered the resistor.
  9. benthic

    benthic glutton 4 punishment

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    Great information from everyone! Thanks! One thing I don't remember reading - if I WANT the "idiot" gen light, is there a specific kind/size filament bulb I need to buy? I might wire my 2853 up this weekend...
  10. craydds

    craydds Long timer

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    See post #324 above as an example. I think most types of warning lamps will work, but I think it should be an incandescent bulb, not an LED (I'll check with ignatz72).
  11. craydds

    craydds Long timer

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  12. benthic

    benthic glutton 4 punishment

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    Snowbum says :Resistor discussion: Nearly any type of resistor may be used. It can be the old-fashioned type called 'carbon composition', or any modern type of 'film' or 'deposited carbon' type....or even a 'wire wound' type. The resistor value CAN be 470 ohms, but my tests indicate that 330 ohms is better.


    from the same Snowbum article: The GEN lamp is rated at 12 volts and 3 watts. Ohms law says that the lamp resistance is 48 ohms when energized by 12 volts. I guess I'll poke around an autoparts store or radioshack...

    EDIT: found this from Snowbum too about the Gen lamp:recommended 168 lamp = 4.90 watts, .35 ampere, rated 1500 hours, a.c.

    Thanks!
  13. craydds

    craydds Long timer

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    Good info, thanks. I'll check the spec's on my little red lamp.
  14. craydds

    craydds Long timer

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    Tach cable has to go:
    [​IMG]

    Gone:
    [​IMG]

    Now, what do I do with the "hole" ? And the rubber grommet? Is there a solid rubber grommet - no hole for the cable?
    [​IMG]

    Any ideas? What have my fellow inmates done?
  15. benthic

    benthic glutton 4 punishment

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    I started hooking my Acewell 2853 up to my 1978 R80/7 today. it all went fairly well. My wire colors don't match what's been noted so far, but i think I've got it worked out.

    My layout is:

    Acewell--------------funtion----------------- BMW
    orange-------------- turnsignal -------------new wire from signal
    light green--------- high beam ------------ white
    light blue -----------haz/Brake fluid -------blue/brown
    purple--------------- nuetral ---------------- brown/black
    gray -----------------oil pressure----------- brown/green
    white ---------------- turn signal ----------- new wire from signal
    black ----------------ground -----------------brown
    brown --------------clock power -----------new wire to battery
    red ------------------speedo ilumination---gray/black
    blue --------------- fuel ---------------------- no match
    yellow ------------- tach --------------------- black

    left over bmw wires:
    black/white - capped and using the new individual wires

    blue
    blue/green

    I used the blue and blue/green as described in craydds' sketch below except i didn't wire into the acewell red, but the warning light I bought didn't come on... everything else appears to work though, so i'm wondering if i just got the wrong light.


    no pictures of my rat nest, i'll just embarrass myself;)
  16. bpeckm

    bpeckm Grin!

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    I simply used some black silicone caulk to fill the hole in the rubber grommet... Later front-covers (after the electronic tachs came in ('+78?)) don't have the notch for the rubber grommet, if you would want to go that way....!

    I also used some high-melting-point grease, like wheel-bearing grease, to plug the hole inside the front cover where the tach cable had been.....

    :D
  17. craydds

    craydds Long timer

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    Thanks, bpeckm! Good solution. I will order a new grommet, because the old one is splitting into pieces.
  18. craydds

    craydds Long timer

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    On my bike ('75 R90S) the grey/black is for instrument illumination, but is positive (+) only when the headlight is ON. That is why I used the BMW green/black connected to Acewell red; green/black is (+) when key is ON. On your bike ('78) the grey/black is (+) always when the key is ON ?
    Good luck on your generator light. Test the lamp separately to make sure it lights up.
  19. Blane

    Blane Been here awhile

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    If you find one let me know. I don't think they sell those seperately any more.
  20. craydds

    craydds Long timer

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