Motogadget M-unit and charging issues

[beerson]

Don't let the length of this post scare you!!

I've found a lot of helpful info on issues with charging but I haven't seen anyone with the same issues that are running the Motogadget M-unit.

My symptoms are basically the same as everyone else's with the exception of how it's all wired up. The bike is a '77 XS360 and basically won't charge the battery. The voltage doesn't rise at all when the bike is running, it just slowly counts down like a time bomb.

I've done all the resistance tests with my volt meter and the coil is reading 4.5 so I think it's ok. The stator is reading pretty much 1.0 across the board instead of .7 even after I've repaired the wires (that weren't broken in the first place).

Rectifier is a rec/reg combo with 3 white, 1 red, 1 black, 1 green, and 1 brown wire.
White wires are wired to my stator, red I have to + and black is grounded on the frame(which I think is correct although black on some regulators is a + wire)
Green goes to green from the coil and the coil is grounded to frame.
Brown I have wired into the lock position on my M-unit since I don't have a harness to feed it back into.

If anyone sees a problem with how I've wired it up or has any experience with the Motogadget m-unit, please help!!! I'm supposed to be taking a trip in a couple of days on this bike and other than the charging issue, it runs great!

Thanks in advance!!

 

[beerson]

I was told with the bike running, I can test the stator unplugged and I'm supposed to get around 60 volts. Is that correct? I'm getting nothing at all...

 

[beerson]

Well, it's charging alright. Not regulating the voltage correctly though. Just grenaded my battery about a mile from my house.

 

[Grimmitar]

Looks like no one responded since you posted 2 years ago. I have a similar setup, but have a ‘79 xs400(2F).
I have a motogadget m.button and m.unit blue. I replaced my contact points with an electronic ignition which works great with stock wiring harness.
I ripped out my old stock harness and ran my own.
I bought a Rick’s Motorsports R/R (model 10-411). The wiring is different than stock:
6-pin connector:
x3 yellow => x3 white alternator
x1 green => black to ground
x1 red => +battery pos
3-pin connector:
x1 white => brown connecting to ignition switch, starter solenoid (red/white wire), and m.unit lock
x1 black => green to ?
x1 green => black to ground

From my starter solenoid, it’s going to engine frame for ground, to battery positive, to m.unit positive, then there are two wires: blue/white going to start output, and red/white going to switched power (brown wiring connecting to m.lock, ignition switch, regulator (regulator white).

I get power to all my lights and everything. I can’t get the electronic ignition to start. I have the coils plugged directly into the ignition out on the m.unit blue. I’m not using any kill switch of any kind or the starter relay. What am I missing?

 

[Timothy Kelly]

I’m interested to hear if you got this up and running!
I’m reviving a 1981 XS400S. So far the rewiring has gone smoothly with the M-unit Blue, but I’m at a loss as to how I connect the Igniton Output from the M-unit. I have the l/w (blue and white) wire from the starter solenoid in the Start Output. With the r/w from the starter solenoid spliced into the r/w from the Igniter the motor cranks, but when I remove it and replace it with the Ignition Output wire nothing happens. Do they both need to be spliced into that wire? Or should I just splice the starters r/w into 12v+?
To clarify:
I am using a 5button setup, with a run/kill switch as opposed to just using the kickstarter.

 

[Grimmitar]

I got mine working the issue was my starter solenoid went tits up (tech speak for shit the bed).
I went to Home Depot for a tractor 12V starter solenoid and it worked like a charm.

I don't remember how I have mine wired. I will go out and take a look, take photos and post again.

 

[Grimmitar]

I have the b/w from the starter solenoid to the m.unit blue start the red/w, or kill switch isn't connected.

 

[Jeff0133]

The ignition output on the m-unit powers the coils and the tci

 

[Timothy Kelly]

So @Grimmitar you left the red/white wire from the solenoid completely unconnected?
@Jeff0133 I understand that the Ignition Output is to power the ignition coils and Igniter, I’m just unsure of how to wire it? I spliced the Ignition Output wire into the red/white wire of the Igniter but nothing happens when I press the Run button.
The wiring is a bit hectic but I’ve attached some photos so you can see the current setup. I’ll be disconnecting the red/white from the starter on Grimmitars advice.

 

[Jeff0133]

Ok...so...you need to study the oem wiring diagrams from the bike as i have wires two bikes with m-units and they are very different.
On the first one the starter solenoid had one signal wire which i connected To the start output...and the tci was powered by the red/White wire directly.
On the second one, the solenoid had two signal wires,one connected To me start output and the other To ground.the red/White wire powered the coils and then went back To the tci To power it.
Now remember...starter solenoid is connected directly To positive pôle then to starter which grounds itself through the engine...