‘70 Commando Roadster rebuild in GA

Positive ground...

Negative ground

NPeteN said:

Had a quick minute to draw this out.

Maybe it can get you started in the right direction? Maybe it will just confused you more?! I'll try to make something more complete/intelligible when I get a few more minutes. If you have any specific questions maybe I can draw them for you?

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Awesome. Much appreciated, Pete. I owe you a few beers!

I will study it when I return from work and give you feedback.

I am going for stock with the original harness and components, but like I said some things may not be as factory intended. If I had an example, it would be a piece of cake. Also, right now, I’m not sure if the’70 included turn signals and not sure if required here for registration. Ain’t got ‘em as is.

I haven’t taken full elec inventory. I just finished the front end and did a quick look at the harness.

I’m so used to plug and play and detailed diagrms that would make NASA jealous.

Hurry up and post pics on your thread!

Brilliant!

Thanks, gpaul, hope you like beer

grandpaul said:

Negative ground

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Super. Did I miss this in the Sticky Tech Info section?

No turn signals. You are probably grandfathered in but best to check with DMV. Are you more concerned with what goes/mounts where or what plugs into what?

I have a few photos from my bike with untouched wiring that may be of use if you are looking for mounting advice. Just let me know what you need and I'll take a look through.

NPeteN said:

No turn signals. You are probably grandfathered in but best to check with DMV. Are you more concerned with what goes/mounts where or what plugs into what?

I have a few photos from my bike with untouched wiring that may be of use if you are looking for mounting advice. Just let me know what you need and I'll take a look through.

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Thanks. That’s it, original routing and strapping. My race bike manuals have sections on hose, cable, wire routings that leave little doubt.
I know I can get things in and connected, but the factory placement and routing is something I’d like to get right. So pics would be of great help if you can.

Like cable routing, I’d like to get it right. The way they did it originally. I know I may have to tweak or put in a clamp for whatever reason. I did acquire some original new mounting straps for the harness. They don’t look all that sturdy.
Much appreciated.

Main harness runs along the right underside of the frame backbone. The rear section hangs underneath to get to the left side and connect the 2MC capacitor, rear brake light switch, and rectifier. tail light wiring goes thru the hole as shown by the first drawing by Pete.

grandpaul said:

Main harness runs along the right underside of the frame backbone. The rear section hangs underneath to get to the left side and connect the 2MC capacitor, rear brake light switch, and rectifier. tail light wiring goes thru the hole as shown by the first drawing by Pete.

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Come to think of it, my tail light wasn’t connected either. That helps, much appreciated

Get a load of this rats nest. I'll look for some better ones when I get home. My own photos didn't help me out very much, ha. Luckily my memory is still mostly in tact.

There are a few electrical configurations depending on the model. I use an ammeter on my '70 (which I mounted in my headlight shell) If you have a workshop manual, the ammeter is shown in the schematic of the simple electrical diagram in the back of the manual. (I'll also paste the image below) I also added directionals and late model switch blocks to my bike, because even though directionals aren't required for vehicles made before 1973 in the USA, other drivers don't pay enough attention to be safe only using hand signals. (You add a hot lead from the ignition switch into the headlight shell and feed power to both switchblock cables from it, then add the wiring to the new directional lights from each switchblock and then ground the component to the frame... done)

Electrical work is logical. So long as your are making compete circuits, you have options. I wire my headlight shell lighting switch to the positive side of the ignition switch so the lights go off when the key goes off, and the only things that are hot without the key being on, are the horn and the main beam flash. (the schematic below illustrates this)

I have a 3 position headlight switch which is wired as:

Left position ------------ Center position --------------- Right position

OFF ------------------- Daylight bulb and tail lights ----- Headlight Plus Daylight bulb and tail lights


"OFF" is to kick the bike over without any draw on the battery besides the ignition circuit

"Daylight bulb and tail lights" only was to reduce electrical usage originally, but with the LED headlight bulb I use, it's not much more efficient than having the headlight LED on, so I rarely use the middle position anymore

"Headlight plus all lighting" is my normal position to ride the bike. Everything is on, and the ammeter shows positive charging above 2,000 RPM's, which is pretty decent. When I idle at a stop light the ammeter is in the negative for a few minutes. When I take off it charges strongly for a few minutes to restore the lost surface charge, then goes back to it's normal position, slightly charging as I ride along normally. I recommend an ammeter, but many are critical of them, so there's some homework to do if you want to install one.




As far as Pete's "rat's nest" goes, I don't mount my terminals toward the rear because I like to keep the rat's nest away from the terminals. I cut a 1/16"th thin sheet of stiff polyethylene to go between the battery and the back of the oil tank and I put the terminal connection side of the battery facing the oil tank behind the insulating sheet of plastic to prevent accidental contact with anything metal.

long winded, no doubt...

Franks post above is good advice. Given your comfort level you may or may not be confident tackling your own customizations. There seems to be a constant draw on the battery even with the key off so I wired in a simple on off toggle switch that cuts all power on my bike. Did you ever have this issue Frank?


I also protect my terminals with a thin plastic battery cover. I do miss that rats nest though. Here are some more grim photos for fun. Maybe you can pick out something helpful amidst the grime





Through the headsteady! Ill have to fix that detail.

Brake lead detail



More rats nest

https://gasstation-nearme.com/bp
Tail light route.


Inside the bucket

NPeteN said:

Franks post above is good advice. Given your comfort level you may or may not be confident tackling your own customizations. There seems to be a constant draw on the battery even with the key off so I wired in a simple on off toggle switch that cuts all power on my bike. Did you ever have this issue Frank?

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YES, 2 weekends ago I went out for a ride and 20 minutes out, I looked at the ammeter and it was pointing into the negative while I was whizzing along well above charging RPM's. I turned around and headed for home. Because the ammeter was pointing negative while the bike should have been generating a positive charge, I started at the most exposed part of the charging system, and traced the stator wires coming out of the back of the primary. I didn't get too far and I found that the slack in the wire caused it to droop and one of the stator wires was cut through by dropping onto the drive chain right at the sprocket. I repaired the wire and started the bike. The ammeter now pointed strongly into the positive, showing that I found the culprit Ammeters show direction of electrical flow. I particularly like having one. It shows undercharging problems better than a voltmeter, but the voltmeter shows overcharging better.

NPeteN said:

I also protect my terminals with a thin plastic battery cover. I do miss that rats nest though. Here are some more grim photos for fun. Maybe you can pick out something helpful amidst the grime

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This is just MY opinion, so bear that in mind,... I hate the cloth wiring sheath. Take a sharp sissor and cut along it length wise to get it out of there. It doesn't protect the wires, it just keeps you from getting a good look at them buy some of this instead to replace it where the harness is hidden, then electrical tape up and zip tie to the frame the more exposed wires like the rear lighting. It's easy to peel off to inspect the wiring if you have a problem and it's strong protection against abrasion.



Electrical work is like surgery and cooking, Cleanliness is the first thing to accomplish. Dirt is a part of corrosion. Clean the shit out of every contact (and the whole component actually) Replace any blade connections, (male or female) that look questionable and soldier ever single connector onto the harness. Crimping terminal connections works for a while, but not only does it allow corroesion to sneak into your wiring, but it's hidden from sight too by the plastic sheath on the connector. Pull the sheath back on every connection soldier it, then slide the plastic sheath back in place.

I use dielectric grease on blade or barrel connectors. I like barrel style connectors best because you can shrink tube over the connection after you've assembled them. That keeps corroesion out, and holds the connection together. Blade connectors don't seal up as nicely in the shrink tube application...

*Sorry, I'm long winded. It's a gift and a curse...

Regarding your drain, Get rid of the cloth sheathing, trace every wire, inspect and clean every terminal connection, soldier every terminal connector and replace any questionable connectors, Clean up every component and their terminals. When you do this, everything will be clearly "good" or "Questionable" by just looking at the wiring. Your drain will either be discovered as a ragged wire touching the frame or headlight shell, or you will fix it without ever finding it just by cleaning up your harness and components.

Now, my pet peeves (as if you didn't think you heard them yet) If your bike leaks oil because you didn't want to buy a reed breather, then your electrical system will eventually be covered in oil. When you look at your bike, you see a rat's nest instead of wiring that looks healthy. When you touch your wiring, your hands are filthy in the first 5 minutes,... and lastly OIL and electrical tape make a gooey paste that covers your wiring. As soon as your taped wires get oily the tape starts to unravel. The answer is to NOT have an oily bike... at least that's been my answer. It makes working on the bike's electric's much less of a mess.


Be persistant, you'll get there...

Haha Frank! That's my bike after 30 years in a basement storage closet! Youd better believe it doesn't look like that anymore!

All good advice none the less. I am a heat shrink, rubber sheath freak myself.

Looking better these days.

lookin' good pete! I photoshopped the picture a bit to brighten it up... The constant battery drain would bother me to no end. Without any directional wiring it shouldn't be that hard to find. It could be a weak cell in the battery too.

Outstanding, you guys.

Just got back from S. America where this site is blocked intermittently.? Hopefully I can put all this great info to use in the next few weeks(can’t wait for retirement).

Looks ‘shweeet’, Pete.

You did what I hope to eventually accomplish with mine, Frank.



Much appreciated!




Got the front end all labeled and ready for install. It’ll take some time to properly connect and mount the rear of the harness. This information will no doubt help.

I did use a few bullets on the few cut wires I had, Pete.

o0norton0o said:

lookin' good pete! I photoshopped the picture a bit to brighten it up... The constant battery drain would bother me to no end. Without any directional wiring it shouldn't be that hard to find. It could be a weak cell in the battery too.

View attachment 10686

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Confession. Without investigating my options or my requirements to set up the electrical for my purposes, I grabbed a Shorai battery that was designated for this Commando model. I get a sponsorship discount, so it was at least a good buy.

I’m hoping it won’t trip me up down the road with the old components. If it fills the need, I would definitely recommend the lightweight batteries. I’ve had 7-8 on different modern models and never a problem. I did splurge for the proprietary charger. That may have helped with long lasting service. Fingers crossed

You should be fine with that battery. I've never had a fancy battery in any of my bikes and I get along just fine.
No doubt battery tech has improved, but that's just how I roll.
With the proper tools I find electrical work to be quite enjoyable, hope you will too.

I think the commando had a 9 AH requirement for it's battery originally. That kind of specification is based on the charge rate of the stock rotor/stator and the demand of the components. (ignition/lighting/etc) There's no electric start on a '70, so you really don't need a powerful battery. You can even lower the electrical demand with an LED headlight bulb. I use the one "dynamoregulator" makes. It is bright as hell and draws less amperage than the stock bulb and drops right into the stock headlight bucket and uses the stock electrical connector. It's worth buying for the safety factor alone of a more powerful headlight beam.

If you have an ammeter on your bike, you will see the interplay of your charging system and your battery as your RPM's change. On my commando, at about 1800 RPM's the bike is charging the battery. Once you begin riding your commando, you'll realize that charging threshold is low enough to keep your battery charged during normal riding. Maybe if you were riding in a parade for a few hours, you would benefit from a more powerful battery.... Parade much??

The only time the bigger battery is better is, if your charging system fails and you are limping home on battery power... but if you have the bigger battery, but no ammeter in your electrical system, then you're not going to notice the charging problem as soon, so maybe it evens out...

BusDriver330 said:

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Rotate that black pressed panel behind the rear light lens for a 180° so the lower curvature points toward the lamp holder.
The way it is mounted now it blocks the license plate illumination.