M-Unit - alternatives for central electrics?

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

  1. Airhead Wrangler

    Airhead Wrangler Long timer

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    Mine is going to live under my tank, so I'm going to have to come up with some kind of cover to keep any water spray and mud out of the connections. Maybe an otterbox or something like that with a couple holes drilled and rubber grommets to seal wire penetrations. Hmmmmm. The clear ones would allow you to see fault LEDs.

    [​IMG]
    #21
  2. naginalf

    naginalf Handy Schtroumpf

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    First of all, where are you going to get one of those black boxes in 5-10 years, will this company still be in business? Secondly, in 5-10 years, this will fail, guaranteed, maybe even less. I work in the electronics industry and I have 3 words for why no modern electronics will last longer than that: LEAD FREE SOLDER! I've long bemoaned the Council of Europe's lack of responsibility to institute electronics recovery and recycling programs, and instead mandating that all electronics sold in Europe be made with the shittiest solder known to mankind :huh. Personally, I smell a big fat conspiracy. I mean, what manufacturer of electronics WOULDN'T want to use a solder that they KNOW only lasts up to 10 years? Of course, they love this, it's manufactured obsolescence!!! Tin, used in solder, corrodes easily, this corrosion is not only conductive, but also crystalizes, meaning that it grows in whiskers, and as soon as they touch, you have a short. If that doesn't kill your electronics, then the brittleness of the solder will when it cracks and breaks, especially when exposed to temperature extremes or weather (like on a bike). These things usually happen only after 2+ years of use, primarily after your warranty is up, and they are easily solved by adding LEAD to the solder. Ever wonder why your PS3 or Xbox failed so quickly after purchase, you can blame CE regulators. Wonder why your TV failed right after the warranty was up, thank you CE. Ever follow that up by trying to resolder things, only to find glue all over the pins, that's to keep this from happening until the warranty is up, plus it keeps you from repairing it with LEADED SOLDER!!!
    :becca:boid:kboom
    Sorry, about that... that being said, as long as you plan on redoing your wiring again in a few years to install the next great device (probably wireless comm) this seems like a decent idea. Personally, I've accepted it and resigned myself to the disposable future we've now created (although most begrudgingly). This sort of thing is probably why people become grumpy old men.:lol3
    #22
  3. Airhead Wrangler

    Airhead Wrangler Long timer

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    I think the board in the m-unit is encapsulated in a hefty block of epoxy (at least it looks that way in photos, I still haven't seen one in the flesh yet), so that solves the corrosion and vibration issues, but I see where you're coming from. Ultimately, I think it will be more reliable than the stock harness, as in it will stay problem free for longer, but it will NOT be in any way repairable. So I wouldn't be installing this if I weren't confident in my ability to rewire my bike in the middle of nowhere. I can rip a wire from somewhere and get power from the battery straight to the ignition and bump start it to get home. There will always be that fallback. I totally understand where you're coming from though.
    #23
  4. DaveBall

    DaveBall Long timer

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    The lack of quality solder has been around since the mid 90s, maybe earlier. It is a common issue for Dodge mini vans of that era to have a lot of electrical issues that a lot of mechanics just can't figure out. I have fixed at least 20 of them for friends just by pulling the dash guages out and resoldering every connection on them. Put them back together and no more faults, flashing lights, computer issues, stalling for no apparent reason, etc. Some people have spent a lot of money on replacement computers and all sorts of other things that can all be fixed by just touching up the solder joints with some good old fashioned lead based solder, especially the main large plug on the back. I am just waiting for the EPA to knock on my door.:evil

    As to worring about what this unit will be like in 5-10 years, not for me to say. But the stock wiring on my present 2 bikes is well over 30 years old. I clean all connections every winter, when it is too cold and wet to ride. Then I can ride the rest of the year with no worries.

    I think that sometimes people look for a fix for something that isn't necessarily broken. But, if they did not do this, we would surely loose out on a lot of advancements. So, please, anyone that wants to try out these umits, please do so and report back with any installation issues, reliability issues, etc. Maybe some of us old fuddy-duddys will learn something from you younger whipper snappers.
    #24
  5. Airhead Wrangler

    Airhead Wrangler Long timer

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    The only reasons that I'm doing it are:

    A) my stock harness is thoroughly dirty, greasy, oily, old, and cracked and is certainly ready for retirement before it springs a gushing "smoke leak"
    B) my electrical system is VERY modified and half the original harness is irrelevant

    So rather than spending $250+ on a new stock harness plus all the relays, etc, I'll just make a harness to suit the system I have and replace all the relays, flashers, fuses, etc with one slick little box and eliminate a lot of extra junk on the bike at the same time, for similar price and far less effort.
    #25
  6. DaveBall

    DaveBall Long timer

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    Airhead Wrangler, your 2 main points make perfect sense to me. Leaking smoke out of the wiring is a definite no-no.

    If you can, could you post some pics as you do the change over? Just so we see what all gets removed and how it looks once done.

    I have replaced wiring on a few airheads, including both laying in a stock harness from a donor bike and making my own. Everything from just the sub-harnesses to everything frmo one end to the other.I found making my own was actually a very easy process, except for sourcing a few of the connectors. I think the hardest is that monstrosity that plugs into the guages. It is basically unobtainable, so I made up a bunch of connectors and then encased the whole works in some epoxy resin. Wasn't all that pretty, but worked.
    #26
  7. Airhead Wrangler

    Airhead Wrangler Long timer

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    Sure thing. It won't be for quite awhile though as I can't return to the US (where my bike is) until next year. :cry

    The ST has it's own which is similarly non-existent in the rest of the world and NLA from BMW.

    The white one on the right:
    [​IMG]
    #27
  8. Bill Harris

    Bill Harris Confirmed Curmudgeon

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    Call me a Luddite. Several years ago I bought the /5 and having little or no money in my purse, patched, repaired and cajoled the stock wiring harness-- never mind how long precisely-- til it was about to give up the ghost in majick smoke a couple of years ago and I replaced to whole harness for the princely sum of $60, US, before becoming an orphan.

    A blackbox ain't worth it... aye, no.

    --Bill
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  9. Airhead Wrangler

    Airhead Wrangler Long timer

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    Prutser, or anyone else who's installed one of these: I have a question about the start and kill switches. The instructions say that you can use a single momentary switch as both the starter button and the kill switch. Push the button and hold to start then "double click" the button to kill the engine. So once the engine is running does the m-unit have some sort of interlock to block use of the starter with this button and only respond to a "double click" of the button or will it still allow you to grind your starter on a spinning flywheel if you accidentally hold the button? They also have an option for a separate kill only on/off or momentary switch. Third, it says you can kill the engine by holding the high beam and left turn signal at the same time.
    #29
  10. Rob Farmer

    Rob Farmer Long timer

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    I like the idea of those M Units. Are the relays replaceable? What current can they switch?
    #30
  11. Rob Farmer

    Rob Farmer Long timer

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    Way too complicated. KISS logic is the way to go.
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  12. Airhead Wrangler

    Airhead Wrangler Long timer

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    No relays, it's all solid state with built in fault detection that automatically cuts power to a circuit in the event of a short. Read the manual here. It shows the max load for each circuit in one of the diagrams. With his setup, near zero load is going through handlebar switches. No relays or fuses required either. The downside is that the only replaceable part is the whole unit.

    http://motogadget.com/media/downloads/manual/munit_v2_manual_en_3.1_k.pdf

    EDIT: I just looked up the max loads for each circuit:

    L+R turn signal circuits 10A (!) each
    Horn 10A
    Starter 30A (enough to go straight to a Valeo or Bosch solenoid w/o starter relay)
    High and low beam circuits 10A each
    Brake light 10A
    Ignition/Aux 18A

    All switches only take .01A, so very small signal wire can be used.
    #32
  13. Airhead Wrangler

    Airhead Wrangler Long timer

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    Agreed. I didn't elaborate further on the fact that I DON'T like that function and wish it could be disabled.
    #33
  14. Rob Farmer

    Rob Farmer Long timer

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    Great stuff. Thanks

    It's the zero load through the switches that causes most problems on vehicles. At least with a bit of current behind it the crap is generally burnt of the contacts.
    #34