Topic: CB750 custom wiring with M-unit questions

[slikwilli420]

I'll start by saying I know nothing about wiring so speak slow and clearly!

The best option or there for clean simple switches seems to be the motogadget units but it sounds like they only work with the m-unit so I'm leaning toward sanitizing the whole wiring loom.

Here is my current plan:

M-unit
Aftermarket R/R unit
M-switches
M-lock
M-button for cleanliness of bar wiring
Dyna S ignition and green coils
Speedhut oil pressure gauge
Speedhut speedo/tach combo

I want to be as minimal as possible so for now no turn signals or idiot lights are needed.

I searched the forum some but there are a lot of options out there. Is there a diagram for my specific setup so there is NO confusion on my part?

[Retro Rocket]

Calling Cal....

[slikwilli420]

M-button gone!

I forgot tail light so that will be there too. Using an old tail light off a smaller CB.

I guess I can do a horn just to stay legal. And there will be a brake light switch just for the front.

[slikwilli420]

Cal, I'll have a light just no switch on the rear brake, only front. I'll have to dig up the light but here are pics of the gauges.
Oil gauge:



Speedo/ tach:

[540nova]

Looks like the speedo has turn indicators and either a High beam or neutral indicator


1974 CB450, 2006 CBR1000RR

[SDmtnbkr]

Here is my current plan:

M-unit
Aftermarket R/R unit
M-switches
M-lock
M-button for cleanliness of bar wiring - Ditch this
Dyna S ignition and green coils
Speedhut oil pressure gauge
Speedhut speedo/tach combo

It could not be easier.
Horn?
Tail light fixture?
Doesn't the Speedhut gauge have integrated idiot lights?

Why ditch the M-button? It seems like it makes the wiring so easy. Is this because the M-Unit already makes the wiring so easy?

[540nova]

As much as I love the M-Unit, it can be quirky, such as finding your tailight and /or headlights on, in a parking mode, unless you turn off the bike in a certain sequence.
Cal, it would be great if you could one day do a write-up of all the little secrets and shortcuts you've discovered.


1974 CB450, 2006 CBR1000RR

[SDmtnbkr]

Ditch it for 2 reasons:
1 - it's not really needed. Using momentary switches, you can run the wire directly to the m-unit from the switch in a straight shot. This provides 2 benefits; 1 is much easier and simpler wiring. 2 is you can relocate that wire at the m-unit to change the behavior of the button at any time.

For instance, you could initially use the lower button in a 2 stack as your Turn L. Later, you could opt to make that your "Horn" because you prefer the ergonomics. To do so, simply move the wire at the m-unit and you're done.

2 - I have found on numerous installs that the m-button is not compatible with our older ignitions. It creates several conflicts and odd behavior of other lights, and does require full resistor ignition wires to isolate that problem. So it's my opinion that it's not worth the hassle or added expense. And if you do use it, and install it inside the handlebars, they have to be made from steel, not alloy. Not an issue for stock bars, but modern bars or clip ons are eliminated from your choices.

Thanks Cal, this is great info you only learn 1st hand.

[slikwilli420]

Cal, did my pics give you enough info for a wiring diagram? I still need to locate the rear taillight to find out of its 2 or 3 wires.

[horrorbiz]

I am following along because I need to completely rewire my bike and I'm completely overwhelmed.

[slikwilli420]

Cal, there was no model number information on or in the box but I did snap a pic of the wiring diagram for each. Hopefully that is more helpful.

[Blue2swing]

I just ordered an m-unit, m-button, and wireing kit from Revival Cycles. I'm sure I will be having these same questions when the time comes for my install. Can't wait to see what Cal comes up with. Thanks.

[slikwilli420]

Cal, no worries at all. I have not ordered any M-stuff yet, but as I think about getting my bike reliable and clean, looking at the nest of stock wiring does nothing for me.

[greenjeans]

I like the "idea" of the m-unit.   But... for just over $300 you can get a brand new part-n-more wiring harness, new handlebar switches, and a Rick's combo rectifier/regulator unit.   Add another $100 and you can get a new ignition, aftermarket coils, plug caps and a sub-harness for your alternator.   All fresh and clean.  Just an option.

[slikwilli420]

Already kind of down the path of the M-stuff though. I have the M-lock so I wont need a new ignition. The stock switches wont work with my other controls so I was seeking a way to go another route. I agree there are less expensive options but the idea of an entirely new system with modern technology trumps the savings. Besides, considering the massive amount I have in this project already, a few hundred isn't breaking my heart.

[slikwilli420]

Cal, this is really helpful for me to get going. Thank you for taking the time to write it up. I have posted a version with some questions on each part of the diagram I would like clarification on. Thank you again.

[slikwilli420]

SUPER HELPFUL!

The only thing I am still trying to understand is where all the wires from the tach/speedo go (since your diagram only has one black coming from it and the turn indicator wires which are the orange and light blue).

Also, where does the wiring for the oil pressure gauge go?

I see 5 switches at the handlebars for L/R turn (2), Hi-beam (1), Horn (1), and Start (1). Im thinking I will use a 3 button and a 2 buttom M-swtich, sound good?

[slikwilli420]

So the Red/White from my gauge goes to the AUX OUT side, represented by the Black in the diagram? Then the Black from gauge is ground, Yellow to the Yellow on the coil, and so on.

I believe the button on the front is for toggling through menu items so should not need the 6th button. I will buy a 3 and a 2 to keep the option of signals available.

Where should wiring for the oil gauge tie in? Guessing Red/White from the gauge can follow the same path as for the tach/speedo gauge.

[Johnny340]

Subscribed to this thread...Awesome info!! 
I am planning my wiring using an M-unit with GSXR switches.

[Johnny340]

I am planning my wiring using an M-unit with GSXR switches.

Hmmm. This will take a good deal of fiddling to get right.

Yes, I'm thinking some buttons like 'hazard lights' will be inop and others like high beams could be difficult.  I'm hoping I can call on your expertise when the time comes.  I'll start another thread then.

[slikwilli420]

Cal, this has been really helpful and hopefully others will be able to use this for their machines. I have a horde of wire, shrink tube and nylon sheathing ready for this project. I just need to go out and get the unit and switches, then the fun begins!

[Johnny340]

That's part of it. The real issue is the flow of power from stock to the m-unit. With stock controls, the power runs to the handlebar switches, is transferred through them, to the components. With the m-unit, all power comes from the m-unit directly to the component. So in essence, you take stock wires (power supply) and tie them to grind so any switch is actually connecting the ground signal to message the m-unit. Clear as mud?

I think I understand.  So we could utilize stock switches to send the signals (via grounding though) to the m-unit which in turn powers the specific circuit.  I'm still not sure how the high beam signal would work since the m-unit only has one headlight input.

[Johnny340]

The m-unit has a built-in function to toggle between HI and LO. So your switch will signal the m-unit to switch the headlight.

So, any momentary ground will alternate high/low? Or could that GSXR high beam switch somehow change to high beam simply when selected on (non-mometary)?

Side note Cal...I gotta ask, with 737 in your user name, are you in aviation?

[Johnny340]

It can be done with the stock GSXR controls. Part of running the m-unit is configuring the unit when you use non-momentary switches.

Nothing to do with aviation 

OK great!  I see that wink and I call BS...haha
Anyway, I'll stop thread jacking now.  I hope to hear from you when I get my M-unit (which I will now that I know my switches will work) and I start my own thread.  Cheers, John

[540nova]

The M-unit is a beautiful piece of engineering, and anyone can wire them. I successfully wired mine with a couple questions to Cal when I had issues. But if you take it slow, one circuit at a time it all makes sense.


1974 CB450, 2006 CBR1000RR