Reg/Rec to m-unit

[Dangerousdave999]

Okay so im wiring the m-unit and the reg/rec and I'm getting a bit confused which wires go where!

From the reg/rec I have my green and three yellows on the gen.

A red for charge to the battery which is usually connected through the starter solenoid post.

Then a black which goes to my stater magnetic switch.
But where..
The negative pole where the starter motor is connected?

Thanks
David

[JustcallmeMrT]

I'll be watching so I know when I wire mine... A ways off yet. 

[Dangerousdave999]

Im 90% sure the black goes to the starter solenoid.

But saw someone else who put it to the lock terminal on the m-unit. 

[Dangerousdave999]

Most confusing bit is my Starter solenoid has a Yellow/Red for the start button.
But the starter has a Green/Red as well and in the diagram its a Black wire.
So maybe I connect to that instead as that wire connects to the old regulator.

[Lobo]

Dave,

You don't state your bike.... assume its a good old 70's Honda?

On these bikes the black wire is an ignition switched live.... ie will be +12v, but only when the ignition is on.

It'll feed many things.... juice to (somewhere) in the starter circuit, the indicator switches, to the brake light switch, the horn circuit... and so on. It'll also supply 12v to the regulator.... which I (think) is your question. So, (and assuming your harness spec) connect this rec/reg black to any black on the Honda. (wouldn't be a bad idea to check first though the bike black is indeed 12v + at ignition ON)

The Hondas were often wired differently, according to model / market & year. Eg on some the stater magnetic switch was earthed by the start button.... and on others it was fed +12v by the start button.
If your bike is the former... then it'll have a nice ignition switched 12v+ to it ... ie that black wire. (magnetic switch connectors likely BLACK & hatched RED/YELLOW)
If your bike is the latter it may have a continuous striped RED/YELLOW to one side of the starter magnetic switch (12V+ from start button) and GREEN off to the clutch switch interlock.

But you mention a GREEN/RED. The only Green/Red wires I can find are to do with the neutral light... and it's entirely plausible your particular Honda uses this as a start interlock. (I don't have such wiring diagrams) ... In which case neither of the starter magnetic connections will do.. Ie you need to find that BLACK.

Finally, it sounds to me that your using the wrong wiring diagram for you particular bike.  It's bloody frustrating... been there.
With respect to the m-unit I've no idea.. but did find the below.

Treat all I say with caution... I'm no Honda expert! And I say again, no idea about m-units.

Cheers,
Simon

http://www.dotheton.com/forum/index.php?PHPSESSID=vlu8o2hqkhcfght58h8e930bu3&topic=51398.0

[Dangerousdave999]

Dave,

You don't state your bike.... assume its a good old 70's Honda?

On these bikes the black wire is an ignition switched live.... ie will be +12v, but only when the ignition is on.

It'll feed many things.... juice to (somewhere) in the starter circuit, the indicator switches, to the brake light switch, the horn circuit... and so on. It'll also supply 12v to the regulator.... which I (think) is your question. So, (and assuming your harness spec) connect this rec/reg black to any black on the Honda. (wouldn't be a bad idea to check first though the bike black is indeed 12v + at ignition ON)

The Hondas were often wired differently, according to model / market & year. Eg on some the stater magnetic switch was earthed by the start button.... and on others it was fed +12v by the start button.
If your bike is the former... then it'll have a nice ignition switched 12v+ to it ... ie that black wire. (magnetic switch connectors likely BLACK & hatched RED/YELLOW)
If your bike is the latter it may have a continuous striped RED/YELLOW to one side of the starter magnetic switch (12V+ from start button) and GREEN off to the clutch switch interlock.

But you mention a GREEN/RED. The only Green/Red wires I can find are to do with the neutral light... and it's entirely plausible your particular Honda uses this as a start interlock. (I don't have such wiring diagrams) ... In which case neither of the starter magnetic connections will do.. Ie you need to find that BLACK.

Finally, it sounds to me that your using the wrong wiring diagram for you particular bike.  It's bloody frustrating... been there.
With respect to the m-unit I've no idea.. but did find the below.

Treat all I say with caution... I'm no Honda expert! And I say again, no idea about m-units.

Cheers,
Simon

http://www.dotheton.com/forum/index.php?PHPSESSID=vlu8o2hqkhcfght58h8e930bu3&topic=51398.0

Sorry yes its a 1977 CB550 K3 UK bike

I have looked at so many different diagrams I'm loosing track!
The haynes one and a couple online show the black from the regulator going to the starter solenoid.
But as I say it has the Green/Red which links to the kill switch and the clutch switch.

[Bryanj]

The K3 SHOULD have the safety interlock and the starter that provides power to the solenoid so no power wires there, also there is a white wire as well as a green wirs going to the generator field, without the full specs and diagram for the reg/rec you have i cannot comment further only to say be very careful as ifyou connect it wrongly, even for a split second, the electronics will be fubared

[Lobo]

Dave, and standing by to be corrected by folk with genuine hands-on experience.. Bryan etc

The earlier Hondas did not have the start interlock, and were more likely wired as per the top pic, ie the starter switch simply grounding the starter solenoid... which was fed with +12v from the ignition (Black wire). This is what you were hoping for; your manuals suggest - but alas hasn't transpired.

I'm guessing your (later) Honda is wired as per the lower diagram... in that the starter switch now feeds 12v to the starter relay ONLY when you press it. The other side of the starter relay is grounded... but only when the clutch is pulled in to complete the circuit. Bottom line, there is NEVER a 'permanent' (ie ignition switched) live supply at the starter relay. (as borne out by the lack of a black wire)

If your bike IS per the lower diagram, you'll need to go elsewhere for this live feed to your rec/ reg unit and basically any black wire in the loom should do. As I suggested earlier though, do first check it is indeed +12v at ignition ON.

Please appreciate Bryan's comments re frying your m-unit... all my guff above is basic Honda... I have not considered any inclusion of this 'm-unit'

Surely the manufacturer can give specific guidance?

Simon

[Dangerousdave999]

I'll be watching so I know when I wire mine... A ways off yet. 

Thanks for everyone's help.
Figured it out that the black wire from the reg/rec unit goes into the lock port on the m-unit to power the switching function.

Good luck with your's Mr T! any questions give me a shout.

David

[Lobo]

Glad it's sorted Dave...

I barely know what an m-unit is... can you enlighten me / us, what 'advantages' etc is it giving you on an old SOHC?

Not knocking it at all.... it's simply new to me!

Simon

[JustcallmeMrT]

I'm definitely no electrical engineer, and I'm very new to bikes, but I'll give this a try since I'm intending on using one.

The m-unit is an electronic control box that replaces your fuse panel with a microprocessor that deactivates faulty circuits and allows diagnosis using a series of lights on the unit itself.  When the fault is repaired, the circuit is reactivated.  The m-unit controls all the switching of your hand controls via a microprocessor - no mechanical relays to wear and degrade, and reduces the size of the necessary switch components.  It also accommodates the use of LED indicators by having integrated flasher relays, which is a bonus for those switching to LED technology. 

So, if you're keeping stock components on an old SOHC, I'm not sure it provides much of a benefit.  However, if you're replacing/modifying your hand controls and moving to LED lighting, I see the benefit.

For me, it also looks like a nice easy and tidy way to rewire my bike.  Since I'm replacing the hand controls with mini push buttons inset into my handlebar, I'll also be using the m-button to reduce the current running in the wires to my controls in conjunction with the m-unit.

More info here:
http://motogadget.com/en/electrics/electronic-control-box-m-unit/m-unit/m-unit-digit-tastersteuerung-u-sicherung.html
http://motogadget.com/en/electrics/electronic-control-box-m-unit/m-button/m-button.html

[Lobo]

Thanks MrT. A bit of bedtime reading... looks interesting.

Simon