Topic: Where do I Start - M-Unit

[chesterburnet111]

I'm going to be getting my CB550 frame over to the powder coater sometime this month. I've been mocking it up and have almost all of the issues covered and the bike is over at my welder's shop. which is getting me to the point that I dread and and am also excited about. Wiring up my M-Unit.

I figured it's time to dig in and figure this thing out. So this is where I'm at. My motor is built and has an electronic ignition installed. I have bought to date.....M-Unit Blue, Motoscope Pro, Breakout box, a 2 & 3 button mo.switches, no.blaze pins, 2 TST led rear turn signals, speedometer sensor, air temp sensor, mo.lock, led headlight, built in switches on clutch and front brake, rear brake switch, Rick's rectifier, wiring kit, Antigravity battery, new Dynatek coils and a new solenoid.   

I want to start working on my wiring diagrams and am hoping there might be some good examples kicking around that I can use as examples. My skill level is that I can wire up a house from the box out, built speaker crossovers. I've done turn signal shutoff module and changed out relays and a lot of other minor electrical work on my late model Yamahas and part of my job is electronic access control. I think I have some skills to build on.

I was also hoping to get some recommendations for videos and how toos aside for the Motogadget documentaion. I like to educate myself when I do these kind of projects as the learning and doing part is one of the fun things to accomplish.   

[calj737]

Some basics about the mUnit. All the control switches on the handlebars are wired to ground locally, then a single wire to the mUnit as the input. That ground signal on the specific port sends switched 12v to the output side of the device, where you take a single wire to the component and locally ground the component. This is the reverse of the stock wiring. So you can use smaller gauge wire (I use 22awg to the mUnit and 18awg from the mUnit as an example).

The OIl and NEU switches on your bike send a ground signal to their respective instrumentation lights, so those bulges need a powered wire run from the mUnit (use one of the AuX ports for these).

The coils, ignition and license plate bulb I power from one of the AuX ports. The Rick’s wires up without relying on the mUnit. You can choose to run the BLK wire from the Reg to AuX since it will have a reference to battery + for charging state.

Here’s an example of typical wiring using the older model mUnit v2 and no breakout box, but you can get pretty far with it. The best practice is to NOT hook-up the AntiGrav battery while wiring and troubleshooting; use a spare/donor battery. The AG battery won’t last and you can easily deplete and damage it.

[chesterburnet111]

yes

[chesterburnet111]

I forget where I saw this - I have an electronic ignition from Charlie's Place and somebody posted that it does not work with M-Unit. Can anyone confirm this?

[calj737]

There is no reason it won’t. It derives power from the IGN or AUX circuit like any other electronic ignition or standard points and condensers would if used with an mUnit.

[Finnigan]

m-unit and charlies place ignition worked fine on my 450 build

[chesterburnet111]

That's what I would have thought. Sometimes it's difficult to parse through the bull#$%* on motorcycle forums.

[calj737]

I find that logic tends to weed out the bullsheet opinions and anecdotes. The mUnit is NOTHING more than a programmable fuse block. Period. It switches power on and off when you trigger it. There’s no way possible for it to interfere with an electronic ignition for a vintage bike. And it has nothing to do with the charging system either. (In case you ever get worried about the myth).