Old Brits power arc ignition led

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Positive (red) to ground. The side the original Norton fuse is on. I put the short black wire with the new fuse (that goes to the red wire coming from the coil block) on the positive terminal as well. Plugs out and connected. Plug placed on the head near the plug hole to ground it and so I can watch for a spark. No compression of course. Kicked it over a bunch. And nothing.will take it apart tonight after work to see if anything "looks" bad, like a burned spot or separated wire.
 
Joe Schlaberdowski said:
Positive (red) to ground. The side the original Norton fuse is on.
Click to expand...

The original fuse is on the negative side.

Edit: Or, perhaps what you meant (without punctuation) was: "The side the original Norton fuse is on I put the short black wire.....etc."?


Joe Schlaberdowski said:
I put the short black wire with the new fuse (that goes to the red wire coming from the coil block) on the positive terminal as well.
Click to expand...


I know little of the Power-Arc so I'm trying to understand what it is you are doing.

Black is usually negative and according to the Old Britts diagram for positive ground, black (also blue & brown?) connects to the negative side as does module black.
http://www.oldbritts.com/powerarc.html
Old Brits power arc ignition led


"Black Frame Ground -12V from the Mounting Harness" as it appears to say on both diagrams can't be correct for positive ground as ground is red.
 
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The way it was explained in the directions that came with the Power Arc, they had a fuse holder that already had the wires attached. The fuse holder and wires are all in black. Black fuse holder and black wires. Now if you have the standard Norton setup, ground is positive and designated by the red battery terminal and red wires (as I understand things). And then the Power Arc fuse (all black) is to be on the ground side (red) of the battery in this case. To save money they only supply a fuse holder with black wires. They apologise for that. Sooo you use that short black wire and fuse segment, hook it to the positive red battery terminal, and then attach it to the red wire coming from the coil block. But with all the other color coded instructions this started flipping back and forth in my head like a game of three card molly. Maybe I got it wrong, but I don't think so. But if I did will someone please correct me so I can get this dang thing running.
 
Joe Schlaberdowski said:
The fuse holder and wires are all in black. Black fuse holder and black wires. Now if you have the standard Norton setup, ground is positive and designated by the red battery terminal and red wires (as I understand things).
Click to expand...

Yes.

Joe Schlaberdowski said:
And then the Power Arc fuse (all black) is to be on the ground side (red) of the battery in this case.
Click to expand...

It can't be, because that fused black wire is negative and therefore must connect to the negative(-) side of the battery as it shows on the OldBritts positive ground diagram. (Actually as shown on both Pos. and Neg. ground diagrams because black is negative, regardless)
 
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Man, did I say that all screwed up! By the way, when I put it together I did connect it correctly. Looked at it when I got home. At work I was remembering even what I did correctly, incorectly. Yes the fuses, both of them, are connected to the black wire from the coil block. It was the other short black wire that you connect to the positive (red) battery terminal and then to the red wire from the coil block. Oh lord! Well anyway I had it correct when I hooked it all up. Upshot is, no matter the confused baloney I posted, it was hooked up correctly -- and the fuse blew. As I said before I must have shorted it out either bolting the coil block down OR jiggling the wires to get them to fit under the gas tank tunnel. I'll check out the simple stuff and report back.
 
I got some nice little tapered spacers machined for the power arc. They fit the cam taper and also the little aluminum flange bushing in the other end. They are also threaded for the puller. My part centers the disk very accurately as well as being precisely the correct height. I have $40 invested in each one but will take $20 each if any one is interested.
 
I have made a wiring diagram for the Power Arc and how it dovetails in to a stock Commando wiring loom.

Old Brits power arc ignition led
Norton Commando Wiring Diagram + Power Arc


A couple of things to look out for:
  1. do something with the blue and brown wires - they should be connected to the black one if you want the standard ignition curve, not left dangling in the air.
  2. tape off the green wire if you are not using it - it's the signal wire for an electronic rev counter, so you are probably not using it.
  3. don't forget that you need to swap the coil wiring from parallel (where each coil is fired separately to wasted spark series configuration where both coils are fired together.
  4. get rid of the ballast resistor and condenser pack if your bike still has them - they are no longer required.
  5. make sure you don't crush the coils when you tighten them up, this can short out the insides, cause them to overheat, which will fry your new electronic ignition module.
Hopefully this is useful.
 
gtiller said:
don't forget that you need to swap the coil wiring from parallel (where each coil is fired separately to wasted spark series configuration where both coils are fired together.
make sure you don't crush the coils when you tighten them up, this can short out the insides, cause them to overheat, which will fry your new electronic ignition module.
Click to expand...

Can the Power Arc kit be used with the two standard 6V coils?

According to the OldBritts diagram and Power Arc instructions, the kit comes with a dual output MC2 coil with three terminals '+12', 'TRIG' and 'GND'.

gtiller said:
I have made a wiring diagram for the Power Arc and how it dovetails in to a stock Commando wiring loom.
Click to expand...

For the MC2 coil, white would connect to the 'TRIG' terminal, (drawn connected to the standard coil - terminal on your diagram).
Also, the fused (black) wire between battery negative and the MC2 'GND' terminal is missing from the diagram.
 
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Joe Schlaberdowski said:
Yes the fuses, both of them, are connected to the black wire from the coil block.
Click to expand...

Both fuses connected to the black wire?

Edit: The (Old Britts diagram) shows the black wire has one fuse (in the short section).

Assuming the other fuse you are referring to is the main fuse then that should be on the brown/blue wire between battery negative and the ignition switch.
 
You can buy the Power Arc on it's own, or as a kit.

If you use two single coils, it is important that total impedance across the pair is between three and four ohms.

A Lucas 17M6 should each test at 1.7 ohms

My diagram was based on standard coils and didn't include the 12 volt dual output single MC2 coil, i'll make another diagram that includes that if it's of interest to anyone.


The diagram on the Power Arc site is generic (ie not Commando specific), but it's nice and simple.

They are showing a standard coil rather than a fancy one with a constant supply and a separate trigger, which i find confuses most people, as it's not something people have come across before.

Old Brits power arc ignition led
 
L.A.B. said:
Both fuses connected to the black wire?

Edit: The (Old Britts diagram) shows the black wire has one fuse (in the short section).

Assuming the other fuse you are referring to is the main fuse then that should be on the brown/blue wire between battery negative and the ignition switch.
Click to expand...
Hope you read my apology for the confusion I wrote. Of course you're right about the wire colors for the positive ground. When at work and away from the bike I switched it in my mind. My confusion came from the short black wire that was supplied in the kit that is connected to the positive terminal (red) and Then connects to the red wire from the coil block. I must say I was too easily confused. Glad you pointed it out. Double checked when I got home and was relieved (only partly) that I had connected it correctly sitting there with instructions in hand.
 
L.A.B. said:
Both fuses connected to the black wire?

Edit: The (Old Britts diagram) shows the black wire has one fuse (in the short section).

Assuming the other fuse you are referring to is the main fuse then that should be on the brown/blue wire between battery negative and the ignition switch.
Click to expand...
Hope you read my apology for the confusion I wrote. Of course you're right about the wire colors for the positive ground. When at work and away from the bike I switched it in my mind. My confusion came from the short black wire that was supplied in the kit that is connected to the positive terminal (red) and Then connects to the red wire from the coil block. I must say I was too easily confused. Glad you pointed it out. Double checked when I got home and was relieved (only partly) that I had connected it correctly sitting there with instructions in hand.
 
Want to add, all is connected correctly. But no spark. Tonight going over voltages. Several questions: 1) is the ignition module ok (probably ok) if you can see the LED light AND you get a particular level of voltage at the trigger terminal on the coil block. And 2) what would that trigger voltage be?
 
Your trigger voltage should be exactly the same as you are getting across your battery terminals.

If you are seeing less than this, check your earths (could be corrosion around the earth studs, or a bad connector)

The other reason you may see a lower voltage is down to dirty terminals, or bad wear in the handlebar switchgear (ie your kill switch)
You can get a rebuild kit for these https://www.rgmnorton.co.uk/buy/lucas-handle-bar-switch-repair-kit-71-72_4202.htm


If you have a multi-meter, put it into "resistance" mode and check the impedance across your coil.

My Old BBritts kit came with a Power Arc dual fire coil, part number 51-150102 - NOT the three terminal MC2.
Old Brits power arc ignition led
https://www.oldbritts.com/51_150102.html this is the coil i received in the kit from Fred and Ella at Old Britts - as you can see, it has only two terminals.
It looks identical to the coil that Matt at Colorado Norton Works uses (which I also have here for comparison)
 
gtiller said:
Your trigger voltage should be exactly the same as you are getting across your battery terminals.

If you are seeing less than this, check your earths (could be corrosion around the earth studs, or a bad connector)

The other reason you may see a lower voltage is down to dirty terminals, or bad wear in the handlebar switchgear (ie your kill switch)
You can get a rebuild kit for these https://www.rgmnorton.co.uk/buy/lucas-handle-bar-switch-repair-kit-71-72_4202.htm


If you have a multi-meter, put it into "resistance" mode and check the impedance across your coil.

My Old BBritts kit came with a Power Arc dual fire coil, part number 51-150102 - NOT the three terminal MC2.
View attachment 12231
https://www.oldbritts.com/51_150102.html this is the coil i received in the kit from Fred and Ella at Old Britts - as you can see, it has only two terminals.
It looks identical to the coil that Matt at Colorado Norton Works uses (which I also have here for comparison)
Click to expand...
Thanks much! I'll check tonight after work.
 
Thaks for the replys. Got to look at it today. Took off the tank and the cap over the ignition unit (at the end of the cam). Wanted to check the rotation of the slot through the sensor. Holding the plug against the head, my son rotated the rear wheel (in fourth) and the dang thing sparked! I looked up to tell my son that, but he was still rotating the wheel. And I was holding the plug in the air now. Wow was that a nice healthy spark. So here it is. I did nothing -- except -- jiggle some wires perhaps. So the good news for me is the unit from Old Brits is still good. But I've got to be on the lookout for an iffy connection. Has anyone worked out a vastly simplified wiring diagram not ever intended for use on a police cruiser?
 
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