Topic: Wiring Diagram Review? With M.Unit Blue and M.Button

[Rhonda_the_honda]

Hello! I'm still working on the wiring for Rhonda, our 1978 CB750K. I put this diagram together by studying the original wiring diagram and others I've seen on this forum, would anyone mind looking at this diagram and provide feedback? This is my first time making one of these, sorry if it's hard to read.

A few things to note:

• I have not included the horn output: I've purchased a Denali Soundbomb: does this need a relay since it pulls 20amp instead of 12a?
• I'm using the original dash, speedo, and tach but have switched the dash indicator lights to LEDs. I may do the same for the Speedo/Tach backlights, but this will wait.
• I think I'm missing a few wires on the diagram from the speedo and tach, I haven't gotten this far yet.. but any pointers are greatly appreciated.
• I am using an Emgo Honda aftermarket switch (I know, they're crap... I'll switch it out this winter when I can afford a better one). I tested the connections and the one in the diagram worked for "ON/OFF". I'm not concerned with the parking/hazard function.
• The turn signals come on with the key switch, which tells me they're being grounded through the indicator lights (I think). Do I need a special diode to prevent back feeding where they wire is split from the M.Unit OUTput to the Front/Rear Turn Signals and Dash Indicator lights?
• I'm extremely green to electrical work, let alone the m.unit. Am I missing any fuses or relays that are needed, despite the M.Unit's built-in relays?

JPEG & PDF of Wiring Diagram attached to this post.

I'm really sorry for all the questions, I'm trying my best to figure this out.. I'm certain my next restoration won't be so difficult.

[Rhonda_the_honda]

No response from here, but Revival Cycles helped me by sharing one of their wiring diagrams for their current cb750 build. They HIGHLY suggested against using the m.button, so I'll be forgoing that idea.

Attaching their wiring diagram for anyone who needs it...

[jpdevol]

Hmmm...you've changed from using OEM style bar switches to the momentary switches that lend better to the M-Unit. Dash lights Neutral and Oil Press. can get power from AUX2 and the Neutral sw, and Oil sender provide the ground. Turn signal indicator gets grounded and then powered from each signal OUT. The only time you need diodes is if you have but a single dash indicator for both R & L signal but you have one for each side. Taillight can be powered from AUX2 as Field Coil is shown occupying AUX1. Diagram appears to only show brake light currently.

[calj737]

Diagram appears to only show brake light currently.

A feature of the mUnit is a single wire for Tail/Brake, hence the diagram as it is.