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....

[calj737]

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?

[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.

[calj737]

No rear brake? Or no rear switch?
Is the tail light you're planning a 2 or 3 wire?

It would take about 15 minutes to edit a diagram I have, but if you want it color accurate, I need to know the Speedhut gauges specifically you're using 

[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?

[calj737]

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.

[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.

[calj737]

Sorry, Wili, I need the model #s off the gauges for my ease. I'll diagram up your bike using a "Single wire" brake configuration.That's a trick within the m-unit so you can eliminate 1 run from the AUX port. The diagram I send will be a tad rough because I'm in the midst of re-drawing all of them in Adobe Illustrator. Just been way TOO slammed with other things at this point.

I'll try to knock yours out today before I leave on business travel for the week. 

[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.

[calj737]

Willi - I haven't forgotten you, just in business travel until later this week. I'll pop it out shortly upon my return.

[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.

[calj737]

Sorry about the lag time... Been a might busy at the ranch these past few weeks. 

I added (mostly for the benefit of others) 6 switches and the turn wiring even though you indicated you'd not be using it. I did color up the m-LOCK and used stock Honda wire colors for all functions for ease of translation. Hope it makes sense?

[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.

[calj737]

So the PDF I downloaded, doesn't have actual notes, only Yellow blocks. But I suspect your questions are: what the hell is this?

So, top left corner, those are your OIL and NEU instrument lights. You indicated you wouldn't be using them, but others will. The wires (BL/R and GR/R) from the motor switches are the "ground" side, so there is a solid BLACK run to each to provide power.

Just below the Switches, that is a tap into AUX which is 12v Switched power. This is the main power feed to your gauge, and is also used for the instrument lights above. The TURN and HI lights above use this, and they in turn get a ground wire. That big round thing is your Koso 

Top far right, next to the table are the OIL and NEU switches. Per Honda stock colors, OIL is BL/R and NEU is GR/R.

Bottom left of the page is the M-LOCK (or stock keyed switch). You only need to run a hot wire to battery + and a single switched wire (BLACK) to LOCK. The M-LOCK uses BROWN as the switched wire, so it runs to LOCK on the M-UNIT. In this instance, BLACK is ground from the M-LOCK.

Did I miss anything?

[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?

[calj737]

The single BLACK wire is switched power. Look at the table in the top right core to match up the wires from the Koso/Speedhut gauge and the diagram I provided.

Your gauge does not have built in instrumentation lights for OIL and NEU, so you'll need to use your stocks, or rig up something custom. If you use some LEDs, understand the BL/R and GR/R wires from the switches are the negative side, and the BLACK on the diagram provides the power.

A 3-way and a 2-way sounds perfect.