Control wires to M-button then one wire to M unit.
Skip the M-Button, it has conflicts with certain types of ignitions.
Do you need it? Nope. Will the stock electronics do the job? Yep. I do like them, and I use them on all my builds. But, every bike I use them on is a full re-wire, all new modern electronics, and all new non-stock components. So "grafting" modern harnesses to stock harnesses is a major PITA.
The biggest difference in the M-unit versus the stock harness is the direction of power. Stock, the key transfers power to the handlebar controls, then to the component. Thus, the stock wires carry current to/thru the handlebars. With the M-unit, the controls only send a GROUND to the M-unit, then internally, the power is sent to the output side and directly to the component. It matters only from a wiring perspective and it does reduce the gauge and complexity of your harness.
The M-unit still requires an inline fuse (albeit quite small) to protect it from over-amp incidents. Internally, the M-unit separates each function onto its own circuit (TURN L is separate from TURN R, HORN is isolated, and so on) so from a troubleshooting/reliability,
I feel it has some advantages over the stock system. You could lose functions of the indicators and still run the bike as opposed to being dead on the side of the road with limited to no lighting. (By the way, each circuit is also self-resetting in the event of a short).
There are some embedded features like: Integrated Flasher, Low Battery Warning, Auto Cancel for your indicators, Flash to Pass, Strobe on your Brake, % illumination on your indicators as Running lights, Alarm, etc. Maybe these features are of no interest to a "restoration bike" but for a "resto-mod" they're pretty convenient.
So it really depends upon your situation as to whether its a good buy. If you have to replace most of the wiring and components because you bought an abandoned bike, and everything is shot, I'd say do it. Otherwise, a modern ATC fuse panel and some diligence works really well too.
But I like all their products a LOT. They're very high quality, but they do charge for it. Maybe not the product line for many, but for some, its all they'll use after experiencing them once.
There are some tricks to getting the most out of them, but only if you find yourself determined to buy one.
Awwww man,i wish you hadnt opened this thread.now we'll have to listen to cal spout the m unit kool aid
As for this ^^^, what took me 3 days to do for Duster, I could have done in 6 hours with an M-unit if he weren't so damn cheap
Not opposed to purchasing the 3-button motogadget to eliminate hand controls.
You'll need 5 buttons to replicate the stock functions (Turn L, Turn R, Horn, Start, LO/HI). And 6 if you use they electronic gauge (MENU).