Wiring in a Motogadget m.unit blue, advice on what to wire in as 'ignition' ?
Close
    
    
Results 1 to 6 of 6
Like Tree5Likes
  • 2 Post By Miker
  • 2 Post By Swingarm
  • 1 Post By Swingarm

Thread: Wiring in a Motogadget m.unit blue, advice on what to wire in as 'ignition' ?

  1. #1
    Junior Member Miker's Avatar
    Join Date
    Feb 2016
    Posts
    14

    Wiring in a Motogadget m.unit blue, advice on what to wire in as 'ignition' ?

    (2007 TW)

    Hey folks,

    I feel really silly for posting this, but I've just blown several hours going though the wiring diagram and searching here, and still can't get past this one step...

    To back up, I'm wiring in a Motogadget m.unit blue (https://revivalcycles.com/products/m...et-m-unit-blue). I have the accessories all figured out (hard to mess that up), but I'm a little lost in the ignition wiring.

    The m.unit has a series of inputs (brake, headlight, turn indicators, sidestand, etc), that are all activated when grounded (except for the 'lock' input, which is fed from the master switch 12v+). It also has a series of outputs that power all the aforementioned accessories, and can also power the starter and ignition. Despite re-reading the manual for the hundredth time, those are the two that I'm a little unsure about. To be explicit, I need to know where to wire in power TO the 'ignition' system when the m.unit is on... Not to be confused with the master switch or the starter.

    For the 'starter' output I'm planning to wire directly to the starter motor, which the m.unit can drive. But the 'ignition' lead seriously evades me... I was expecting to wire it into the hot lead on the CDI, but none of them come up as hot on my multimeter, and as best as I can tell from the wiring diagram (I'm a bit of a noob), the blue/yellow lead is the closest thing, but that doesn't appear to be hot at all. Looks more like an open ground? Anyway, I swear I'm not burning the bike down, everything else is going exactly to plan (except for when I lost an hour to having the starter relay reversed, whoops. Love those troubleshooting steps in the factory service manual, really bailed me out of that one).

    Apologies for rambling on, I'm a few medicinal beers in, after all 15 or so hours of rewiring work.

    Thanks folks!
    Mike
    Last edited by Miker; 07-08-2017 at 09:32 PM.
    Rockit and Purple like this.

  2. #2
    Junior Member Miker's Avatar
    Join Date
    Feb 2016
    Posts
    14
    Adding a link to ValorSolo's great colored wiring diagrams, just in case: https://tw200forum.com/forum/technica...tml#post106213

  3. #3
    Senior Member Swingarm's Avatar
    Join Date
    Jan 2017
    Location
    Houston Tx
    Posts
    135
    The blue /yellow is the ground for the cdi to run. Remove b/y and bike ignition stops. The ignition is killed by removing ground. It's safer this way as compared to older bikes that needed a ground to kill ignition. Dont power it with 12 v or you may blow the cdi.

    I see that the starter position is good for 30 amps but they are saying that the original solenoid should be utilized. This is what it says...

    "All starters with separate starter relays (e.g. Jap
    anese models) must continue to be operated using
    the original starter relay. In this case, the
    Start output is connected to the relay which switches the
    actual cranking current (>100A). On some vehicles,
    this starter relay is switched using a second
    relay for protection of the start pushbutton. This
    second relay can be dispensed with. "

    They also show on page 11 that they want the m unit to power the ignition such as in a battery ignition system. The TW is a magneto/stator/cdi type ignition system. Traditionally many small engines and motorcycle engines were magneto systems and used a ground to "kill" the ignition through a handle bar switch. The flaw in this system is that you had to hold that button down until the engine stopped rotating. This could be difficult to do in certain situations. The other flaw is that IF anything were to malfunction withing that grounding system the ignition could not be killed. On the TW the ground is broken to kill and it's done through a rocker switch. You could argue that this system could still malfunction with the ground "made". It is true but still less likely and safer than the old system.

    With just taking a quick look at their schematic, they want to see ignition power at the coil. The TW doesnt work by sending 12 volts to the coil it works by grounding the cdi. If you look at the late model schematic that you posted you will see that the TW coil is grounded and fired from a pulse from the cdi. The stator/sensor under the flywheel sends power/pulse/signal to the cdi. The cdi "runs" by being grounded through B/Y and accompanying relays pertaining to safety interlocks/switches. I'm not saying there is no way to make this work but why do you want this gizmo? Not being a smart ass but it's just more complication, I went the opposite direction and want to know in an instant how I can make my bike run and not be troubleshooting anything on the road or trail. Use that smart phone to play ac/dc through a helmet headset.
    Last edited by Swingarm; 07-10-2017 at 04:31 AM. Reason: Woke up with wiring schematic on back of eyelids
    Purple and Miker like this.

  4. Remove Advertisements
    TW200Forum.com
    Advertisements
     

  5. #4
    Senior Member Swingarm's Avatar
    Join Date
    Jan 2017
    Location
    Houston Tx
    Posts
    135
    With thinking about it a little more I suppose you could use a relay that brings in a ground to the B/Y wire when the M unit sends a positive to that relay. Doing all of this does bypass the safety systems so what happens if the bike is in gear? I may be missing something as I only looked at the schematic a little and I dont remember anything about a neutral safety switch in the M unit manual.
    Miker likes this.

  6. #5
    Junior Member Miker's Avatar
    Join Date
    Feb 2016
    Posts
    14
    Swingarm, you're a life-saver multiple times over. I've read that manual cover-to-cover so many times (not the German half, but at least the English part ), but in the wiring frenzy I managed to get way ahead of myself and totally forgot about that block you pasted in regarding the starter. Thank you for saving me from a headache on that one.

    The TW doesnt work by sending 12 volts to the coil it works by grounding the cdi. If you look at the late model schematic that you posted you will see that the TW coil is grounded and fired from a pulse from the cdi. The stator/sensor under the flywheel sends power/pulse/signal to the cdi. The cdi "runs" by being grounded through B/Y and accompanying relays pertaining to safety interlocks/switches.
    Thank you! That's exactly what I was needing to read, and that's exactly what it looks like in the wiring diagram, but I'm only barely competent with electronics, even less so with motorcycle wiring, so I totally doubted myself. The relay idea is very clever, too, but you're right about the safety systems... the M unit has provisions for side stand, however from my understanding it only prevents starting.

    As for why I wanted the gizmo, I had been doing a scrambler-ish/brat-ish build, with a hollow mod and simplified wiring harness and all that, and in the middle of the build I had my first kid. So the bike sat for over a year frozen in time, and I needed some motivation (and time, mostly time) to get back out there... The m units looked like they could really make wiring in all these wacky accessories I've added a little simpler and a little more fun, and sure enough, it did. I even managed to enjoy myself, except for this aspect, which I might be better off leaving alone for now while I get the bike back to a running state.

  7. #6
    Senior Member Swingarm's Avatar
    Join Date
    Jan 2017
    Location
    Houston Tx
    Posts
    135
    Ok I see. my brain is stuck in the rocks and dirt of the desert. If you are doing away with most of the switches and relays that's different too. I'll look at it more some time. So what are the main things you want the bike to do? Remote start may also be difficult if the engine is too cold and needs the choke. We may find another way around the ignition issue. I'll have to look at the neutral switch on the schematic.

    Congratulations on your child as that is such a wonderful thing. My grand daughter is now 15 months old. While I was visiting her this past winter I would take her on my sons quad at creep speed. Yes, I sometimes practice civil disobedience. It is unbelievable how they are watching and paying attention. When she would see the quad parked she would wiggle her fingers and say ruum ruum. My son took her to the store and they passed a guy parked near entrance with a scooter and she said ruum ruum and wiggled her hand and got mad when my son didn't stop. I'll buy her an electric car when I get back down there. I also have an older Honda 50 that I spotted in Bouse last winter on our ride to Swansea. I bought that and a real ratty 1987 TW for the kick starter parts.
    Last edited by Swingarm; 07-10-2017 at 06:38 PM.

Sponosred Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Similar Threads

  1. Wiring a GPS - where do I attach the positive wire?
    By HobbitRider in forum Technical Help
    Replies: 15
    Last Post: 07-30-2016, 10:50 AM
  2. Replies: 7
    Last Post: 08-07-2015, 11:57 AM
  3. Ignition - magneto wire hookup
    By slowmod in forum Technical Help
    Replies: 5
    Last Post: 05-02-2014, 08:46 PM
  4. New Ignition wiring
    By disgruntled in forum Technical Help
    Replies: 0
    Last Post: 06-28-2011, 02:29 PM
  5. Wiring Question - Where does this wire go???.
    By Grant in forum Technical Help
    Replies: 7
    Last Post: 12-25-2010, 12:31 PM

Search tags for this page

wiring cdi to munit blue

Click on a term to search for related topics.