need more help please

Ok so I put the ballast resistor in- great power to the coils. .....but power on both - and + terminals of the coils-not good. So I traced the negative lead from the right side coil to find that it just danglingat the other end in the frame area of the rear of the bike- If I ground the wire I get ground to the coils and spark- yay!
So my question is does anyone know where the white with black tracer wire connects to near the rear of the frame area. I cannot find ground splice near the back, its the wire that provides a ground to the coils


1971 norton commando 750

is it a white wire with BLUE tracer? that's what my wiring diagram shows. if so, it comes from the coil and goes to the harness connectors, where it turns into a white/yellow wire.
hope this helps

Maybe Black with a white tracer? As in Black with a yellow tracer they are the end of the points and have branches for the little can condensers. These cans have there own red ground wire.

powertwins said:

So I traced the negative lead from the right side coil to find that it just danglingat the other end in the frame area of the rear of the bike- If I ground the wire I get ground to the coils and spark- yay!

Click to expand...

No negative wire should go be going directly to ground, as it should be (was originally) a positive ground electrical system, so I don't see how grounding a wire connected to one of the coils' negative terminals would give you sparks, as that would be a short circuit?

I did not touch the wire to chassis ground, which you are right is powered, but I ground it at the negative battery terminal directly. It did have a healthy spark after that

-- also the wire is white with a black tracer coming off of both negative terminals of the coils. both look very factory

Powertwins,
It's been a while since I ran points in a Commando, but if I recall correctly, doesn't the white/black wire run from the ballast resistor to the negative side of one coil and loop to the negative terminal of the other coil? The feed to the ballast resistor should be white with a blue tracer.

Ron L said:

It's been a while since I ran points in a Commando, but if I recall correctly, doesn't the white/black wire run from the ballast resistor to the negative side of one coil and loop to the negative terminal of the other coil? The feed to the ballast resistor should be white with a blue tracer.

Click to expand...

According to the wiring diagram, there's no colour change, it only shows White/Blue? Would the factory have put White/Black and Black/White (points wire) wires so close together, so they would be on opposite coil connections?

Anybody else have a White/Black ballast to coils wire?

Also that ballast to coils wire would be relatively short as the ballast is right next to the coils? As powertwins described it, his White/Black wire runs toward the rear of the frame?

A Lucas RITA AB11 electronic ignition would have had a White/Black negative coil wire - although the coils would have been connected in series to work with the RITA? So this wire could actually be a left-over from a previous RITA installation, where an owner has re-installed points ignition, but used some of the old RITA wiring?

Im not sure exactly, but i do know that 10 minutes ago the commando came to life for the first time(from what the previous owner told me) in 20 years!!!! sounded good idle was wayyy high and things were vibrating off the bike left and right. It did sound healthy, I ran it only for a minute in part because my fuel supply consist of a hose and small funnel ( i didn't want to put new alcohol enriched modern fuel into the fiberglass tank). So now complete tear down and cafe it out!