New Harness for m.unit blue and m.button

[Grimmitar]

I have a ‘79 xs400(2F). My most favorite bike I’ve ever owned, and I’ve owned six.
I have a motogadget m.button and m.unit blue. I replaced my contact points with an electronic ignition which works great with stock wiring harness.
I ripped out my old stock harness and ran my own wiring.
I bought a Rick’s Motorsports R/R (model 10-411). The wiring is different than stock:
6-pin connector:
x3 yellow => x3 white alternator
x1 green => black to ground
x1 red => +battery pos
3-pin connector:
x1 white => brown connecting to ignition switch, starter solenoid (red/white wire), and m.unit lock
x1 black => green to ?
x1 green => black to ground

From my starter solenoid, it’s going to engine frame for ground, to battery positive, to m.unit positive, then there are two wires: blue/white going to start output, and red/white going to switched power (brown wiring connecting to m.lock, ignition switch, regulator (regulator white).

I get power to all my lights and everything. I can’t get the electronic ignition to start. I have the coils plugged directly into the ignition-out on the m.unit blue. I’m not using any kill switch of any kind or the starter relay. What am I missing?

 

[Grimmitar]

Let me add that the left turn signal flashes on the indicator as well as the Turn L LED on the m.unit blue.
Sometimes I get quick flashes of the LEDs on the horn, turn r, and turn l out of the m.unit.
The manual sucks and isn’t very informative. There really aren’t a lot of posts for this type of setup. I’m not very electrical savvy but I have a general idea.

 

[xschris]

You have a 79-2f that has an e-start? You sure it's not a F model. The 2-f came with drum brakes and spoke wheels.

 

[spectra]

I have a ‘79 xs400(2F). My most favorite bike I’ve ever owned, and I’ve owned six.
I have a motogadget m.button and m.unit blue. I replaced my contact points with an electronic ignition which works great with stock wiring harness.
I ripped out my old stock harness and ran my own wiring.
I bought a Rick’s Motorsports R/R (model 10-411). The wiring is different than stock:
6-pin connector:
x3 yellow => x3 white alternator
x1 green => black to ground
x1 red => +battery pos
3-pin connector:
x1 white => brown connecting to ignition switch, starter solenoid (red/white wire), and m.unit lock
x1 black => green to ?
x1 green => black to ground

From my starter solenoid, it’s going to engine frame for ground, to battery positive, to m.unit positive, then there are two wires: blue/white going to start output, and red/white going to switched power (brown wiring connecting to m.lock, ignition switch, regulator (regulator white).

I get power to all my lights and everything. I can’t get the electronic ignition to start. I have the coils plugged directly into the ignition-out on the m.unit blue. I’m not using any kill switch of any kind or the starter relay. What am I missing?

Are you running a Pamco?

I have a M Unit V2 and I run a Pamco. I ran the hot wire from the accessory port on the M Unit to the coils for the Pamco. I did run a kill switch in line but do not really need it. I am not sure how the M Unit Blue works compared to the V2. Is that circuit hot all the time or only at certain times?

 

[Grimmitar]

My model is the F, not the 2F. It has disc brakes both front and rear.
It came with contact points but I replaced them with Pamco electronic.
The m.unit blue has an ignition-out port. It also has aux 1 and 2 in and out. I use aux 2 for powering my neutral and oil lights in the speedo which are also 3rd party (DCC).

 

[spectra]

But is that ignition port hot all the time? Also whats on the in side of that port?

Also what Pamco unit do you have? I have an older one and still run my weights from the points. I think its one of the original units from Pamco.

 

[Grimmitar]

It is hot all the time. I’m wondering if the coils are not receiving enough power (measured in volts, amps, xx?).

It’s a newer pamco electronic ignition. The points were ok but the engine would misfire a lot between 1.8k rpm and ~2.8. The battery also kept losing charge, so I replaced my regulator and rectifier with rick’s motor sports 10-411 model. I don’t like the wiring color scheme they use because I had to guesstimate the regulator wire scheme and match it with mine.

The engine starts with just one lazy kick and purrs very nicely, idling at 1.1k rpm. No more misfiring and I haven’t been able to ride to see if the battery is being charged by my new R/R combo. I’ve been busy rewriting everything. I’m thinking I may have to reintroduce my starter relay...

 

[spectra]

If it starts and runs then the Pamco is working. If it wasn't you would have no spark.......are you saying the starter will not work?

 

[spectra]

Kind of lost as to what your issue is now..........

Who did you purchase the M Unit from?

I dealt with Revival Cycles and there tech team is great if any questions. I am kind of a homer for them now as they have answered a few questions for me really quickly.

 

[Grimmitar]

I’m saying my starter (push start/electronic start) isn’t working. I have my start button control switch connected to the m.button and grounded. The m.button is connected, via green wire, to the m.unit and is also grounded. The ignition coils are connected to the ignition-out on the m.unit. The blu-white wire from the starter solenoid is connected to the start-out on the m.unit.

It’s not starting using the electronic start.

 

[spectra]

Ah ok what starter relay are you using?

I just ran with an after market one as I gutted all the factory wiring and ran my own.

I am thinking it has something to do with the relay.

 

[Grimmitar]

I took the stock starter relay out. I didn’t realize I still needed this. Haha dangit!

 

[Grimmitar]

How would I wire up my starter relay now? The yellow goes to the alternator, black to ground, blue/black to ??, red yellow to ??

 

[Grimmitar]

So, I guess there is a safety relay, which is what I’m referring to in my above post. Then there’s the starter relay solenoid. I believe mine’s done, kaput. How can I test to see if it is even working or not?

 

[Grimmitar]

I figured it out. My starter solenoid was the culprit. There was no clicking sound when I pressed the start button.

I used my voltmeter and tested the terminal that the starter motor connects to. I did this with the ignition switch turned on. No volts.

I went to Home Depot, bought a 12V tractor solenoid for $13 and some change and swapped out my Hitachi 12v A104-70 model solenoid. Viola!

That safety relay is hitting the junk pile now, as well as my old fuse box, control switches, mirrors, r/r, bad starter solenoid, wiring harness, fenders, speedo, and tacho.

I’m loving the look of my new machine.

Thanks to all those xs, and other motorcycle gurus, for all your experience and info. I did a lot of research to get to the point I’m at now.

 

[xschris]

Post your junk in the classifieds for sale as some people my need them.

 

[spectra]

Good to hear you got it figured out.

And yes post up your stuff someone may need it.

 

[BBS360]

Yeah. That wiring harness could save someone's bacon.