M-Unit - alternatives for central electrics?

Discussion in 'Airheads' started by Basic_Gerd, Oct 7, 2012.

  1. Basic_Gerd

    Basic_Gerd Gerd

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    Hi,

    which suppliers do you know for a centralized electrical unit (redesign of the 2V electric system)? Goal is simplification in terms of number of components and wires without loss of functionality (in the contrary: gaining some nifty, albeit not mandatory features along the way).


    I am aware of:
    1. M-Unit: seems to be #1 over here, but I think the US "tinker" scene and the whole market is much bigger. Units like that are also used by choppers or streetfighters - which doesn't devalue the component as such in the first place :D.
    2. "F Box plus": quite similar, but obviously less popular (units sold).
    Any more? Good reputation? Reliability?

    Preliminary note: a discussion about the "why not stock?" wouldn't be very helpful at least for me.
    Thanks!
    #1
  2. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    That appears to be a consumer-grade aftermarket CAN-Bus. That system is a major PITA on the new BMWs.

    No way.
    #2
  3. Prutser

    Prutser Long timer

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    Would you like to put it on the 80GS ?

    I really like the M-unit. But to be honest i don't know that much about the "other option"
    If you would like to make the wiring simpler by using the M-unit you might have to lose some original features.
    Switching off the indicators using the original switches you might have to use the on button to switch them off as well.
    Using the clutch switch and neutral switch in the start system might add some extra wiring out side of the M-unit.
    The same with the Relief relay ( if thats the right word) that switches off the head light when starting.

    Besides than that I love the thing.

    Maybe other inmates can tell you more about the pros and cons .

    Good luck with your choice.
    #3
  4. Basic_Gerd

    Basic_Gerd Gerd

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    Not my basic, but a new HPN project.
    This is about the only point I did not find in their documentation. And: no stock functions will have to be dropped. You can, but you don't need to.
    Well: sure threre will be some wiring left - from all the switches to the m-Unit and power lines back. "Neutral" is integrated, "clutch" I could definitely live without, "kill" is easy. The functionality of the relief relay is inside the m-Unit, as well as blinker and all the rest (except heated grips).

    But I'm not with the sales dept. of these guys, I'm looking for experience.

    @Bill: no, it's not. There's a looong way from this to a CAN bus system. It's a replacement for all (!) relays and fuses, that's all.
    #4
  5. disston

    disston ShadeTreeExpert

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    I don't have a problem with the stock wiring on my Airhead other than I could maybe use a little more juice. That is provided for with the stock wiring if I want or can pay for it.

    It probably helps that I can read a wiring diagram? Maybe I'm just used to the way they used to build stuff. So if they eliminate all the wiring by putting everything inside a black box, what is the advantage of that?
    #5
  6. Airhead Wrangler

    Airhead Wrangler Long timer

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    I have no experience with the m-unit, but I also ordered one for use on my HPN project. I won't get around to installing it until sometime next year though. I'll be watching to see what people say here though. The only thing I don't like is if you use the momentary buttons for all controls, then pushing your high beam and turn signal at the same time will act as a kill switch. I don't want that. The other thing I'm looking for are some buttons for the left side controls. Anyone got any great options?

    You'll need to post photos or I'm afraid nobody will be able to help. :D
    #6
  7. Basic_Gerd

    Basic_Gerd Gerd

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    Me too. That's the reason why I wanna simplify it.
    #7
  8. DaveBall

    DaveBall Long timer

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    I am probably way to old school for this. I have no issues with the stock wiring. I also know how to read a wiring diagram. That being said, I have totally rewired more than a few old bikes in the past, usually with a lot less wire and connections afterwards, and a few more fuses. When I used to build street rods, I would always create my own wiring harnesses and proper diagrams. It really isn't all that difficult.

    But, I can see where the next generation will want to take things a few steps further. Those units look kind of interesting, but I think that I would prefer to have some seperate circuits in case something goes wrong with one. I would hate a short in the turnsignals would stop the unit from allowing the starting circuit from working, so I could get the bike home.

    I like the idea of being able to pop in a replacement relay, when one fails, instead of a complete new "brain" which will cost a whole lot more.
    #8
  9. Prutser

    Prutser Long timer

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    On another bike i'm going to use one again. I mounted one on a R100gs( using the original switches)
    And it works super !!! The indicator relay is great. Using it with rizoma led indicators without resistors.
    At the time we mounted it there were only german manuals, that was a struggle for me. That might be why I missed the relief relay function. Great that thats there.
    So for experience......... One verry happy user !
    #9
  10. Prutser

    Prutser Long timer

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    On my ST I'm using a KTM switch. Real simple thing.
    #10
  11. Basic_Gerd

    Basic_Gerd Gerd

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    Thoughts like yours came into my mind, too. And I guess I belong to the same generation as you :D. What still lets me tend towards the m-Unit is:
    • the BMW flasher relay (post 90) is not exactly "industry standard", like some other components. For example, I'd like to have LED flashers on this bike, so the flasher relay would have to be modified. Resitors - no way :puke1 .
    • the post 90 wiring harness is not really known for long term reliability - 20+ years is some time, is it? More than one I know of went off into smoke or caused nasty stopovers. That's why I'm gonna create my own.
    • modern electronic components designed and manufactured properly are very reliable - so the chance of failure is far below that of, say, a rotor or a lot of other "critical" components.
    • all the wires meet in one small area. This makes it possible to create some emergency bypasses, which I will carry along for ease of mind. Together with a "master minus switch" which I will incorporate anyway this will allow a relatively easy emergency operation.
    What remains is the price in case of failure: 250€. That's why I'm so curious for experiences (esp. long term).
    #11
  12. Basic_Gerd

    Basic_Gerd Gerd

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    Thanks alot! That (or the opposite) is what I'm looking for. Since when do you run it?
    #12
  13. Prutser

    Prutser Long timer

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    Its on the bike for about a year now. Not that many km's 10.000 max.

    My only worry would be the cable connections on the unit. The screw clamp connection might come loose when doing proper off road. So far no problems.
    [​IMG]
    #13
  14. disston

    disston ShadeTreeExpert

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    I can see this being an improvement for some, for some bikes. But these machines are some of them now 40 years old and some of them will be on the road 40 years from now. So as all electronics go, what do I do when this unit is not working? How long before the first problems, before total failure? Do I now have something that can't be repaired, I would replace it but they don't make them anymore?

    I think you are striving for a pretty complete redo? How about a smaller unit that only does something that's a current problem, like lights, turn signals and all?
    #14
  15. igormortis

    igormortis Cafe Reise

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    Prutser, did you use this on your overland bike? I've considered this also, for simplification purposes. It seems like it would be straightforward enough to bypass, as Gerd has already said. My main concern was weather and vibration resistance.
    #15
  16. Prutser

    Prutser Long timer

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    The bike is used for both on and off road. We build it in the headlight and speedo housing !
    Not out in the open.

    Finding a faillure would be real easy. The unit showes an led when you use a switch. On the outgoing side of the unit it showes the led if this function works. Must be simple to locate the problem!

    Motogadged has a lot of things developed to use or mount on to Harley's. So I think the vibration testing has been done:D
    But bad weather and off road conditions might be something we need to test ourselves. :lol3
    #16
  17. Basic_Gerd

    Basic_Gerd Gerd

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    @Prutser:
    the GS you mention was a 91 model, correct? So it should have the 3 flasher keys, right?

    If yes: how did you turn off the flashers? I emailed with the m-unit support, because I missed the input for the "flasher off" key. In all douments or wiring diagrams they only mention "left on key" and "right on key", but no "both off". They replied "there is none" and pointed me towards that several "auto off" modes you can program. But that's not what I like.
    I replied once again with the specific question - radio silence until now.
    #17
  18. Prutser

    Prutser Long timer

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    I did not use the Off button. I turn them off by touching the on button again. In the beginning its something u do have to get used to when u are used to the "one" off button.
    #18
  19. Basic_Gerd

    Basic_Gerd Gerd

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    My idea was to connect the "off" button to both inputs. Would that start hazard flasher mode (all on) instead of "all off"?
    #19
  20. Prutser

    Prutser Long timer

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    I'm not 100% sure but I think that will switch on the hazard lights. I don't have the wiring diagram with me at the moment.
    #20