Rewiring 72 norton. Have some electrical ?'s

After pulling the side cover on the bike the other day i noticed dirty, unconnected wires just hanging about and thought this has to be fixed. Its a 72 FB with a 68/69 engine. Ordered 2 (72 and 68) main harnesses to fit. The 60's version fit much better. Everything went pretty easy until i saw i have no condensers, rectifier, ballast resister but i do have a capacitor and zener diode. Im getting a little confused as to which components are needed to keep the bike running.

Are all main harness wires removed from the coils when installing the Boyer micro mkiii box? Or do they get connected to the coils along with the stock harness wires?

If you are using a Boyer then no condensers are needed as you have no points or a ballast resistor as your 6V coils will be wired in series instead of in parallel, but you do need a rectifier to convert the AC output of the alternator to DC for the battery and feeding the rest of the electrics.

You need the boyer installation instructions for a Norton Commando and a rectifier.

https://www.oldbritts.com/boyer_install.html

It will also help if you can sketch out the circuits, ie feed ignition, brake switch, lights etc and this will help you to understand what is needed where and how they interlink through the switches. With this understanding it will make the fitting of the ignition system iaw the instructions easier as you will understand what you are trying to achieve when connecting the wires and what will be left out and why - hope this makes sense, and apologies if you NIC qualified or and National grid repair engineer!!

I'd strongly suggest the 72 harness. For a complete 72 with normal switches, I'd have zero interest in the 68 harness.
The normal 1972 "extra wires" will not be used with the boyer change.
You will mainly need to add a pair of wires from the 68 rear points housing to the boyer box in the coil area.
Otherwise the boyer change will go as normal except the routing of the pick-up wires and rotation direction of the boyer rotor.

added: yes you will need power (and ground) in the coil area from the 72 harness for the boyer. You will need a rectifier. The big cap in the battery area and zener can stay. You don't need the small caps or ballast in the coil area.
IMO a LOT more work to use the 68 harness.

If you're up for a winter job, make your own main harness. With all the right bits and copious amounts of shrink tube, it's really not that challenging, and you'll be able to tailor the harness to suit your needs (in my case, single point ground etc...)

Thanks for all the replies, you guys are great! So today was actually the second say working on this and i had already started using the 68/69 harness and so far Iv gotten just about everything sorted out. Took about 6 hours yesterday and another 4 or so today. So far everything that worked before is working now. There are only 2 problems I'm up against now. The headlight would turn off when i flipped the dipper switch and the kill/horn buttons didn't work so i removed the handlebar switch(which is damaged) altogether. The big problem is that the ammeter is dead center until i turn on the headlight, then it goes to -4. When I start the bike it drops almost to -12. Not sure if the battery is just real low or the charging system isn't working.

Re: Rewiring bitza commando

I think I can't be much further help. I thought you had a 72 which means all 72 electrical equipment. Since you have an ammeter on your bike than all bets are off...72 did not come oem that way. It's a bitza! Each problem will need full wire tracing of each circuit to get a functioning bike. A full OEM harness swap normally should take 3 hrs and 2 more to mod for rear points and the boyer swap. Sounds like you still have a ways to go. :roll:

Re: Rewiring bitza commando

dynodave said:

I think I can't be much further help. I thought you had a 72 which means all 72 electrical equipment. Since you have an ammeter on your bike than all bets are off...72 did not come oem that way. It's a bitza! Each problem will need full wire tracing of each circuit to get a functioning bike. A full OEM harness swap normally should take 3 hrs and 2 more to mod for rear points and the boyer swap. Sounds like you still have a ways to go. :roll:

Click to expand...

Its all good! Its a pain, but i love it. Looks like the bike is a 72 fastback but the PO replaced most everything else with late 60's components. Thanks for everything Dave.

SOLVED! Ok! I tried to use as much of the new harness as possible so when i installed the Pordtronics rectifier i tied the red into the ground wire coming out of the new harness. Turns out it had to go to the battery for the ammeter to get a charge reading. This threw me off because i got a charge reading from the battery with a multimeter when the bike was running. Thanks everyone fore the help!