1962 650 SS harness
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texasSlick
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I very much doubt Lucas invented the Zener Diode.
The '62 Atlas did not have a Zener Diode. The voltage from the stator was controlled by matching the 3 wire stator coils to the load. This matching, crude at best, was done by the main lighing switch.
Slick
The '62 Atlas did not have a Zener Diode. The voltage from the stator was controlled by matching the 3 wire stator coils to the load. This matching, crude at best, was done by the main lighing switch.
Slick
Hi Slick,
i understand.
But my 1964 G15 (same Atlas engine and harness) has 3 wires stator coils that go to rectifier snd lightning switch; but has Zener diod!
What the differences?.
Thank you.
Piero
The Lucas alternators were originally 6 volts, and when the Zener was made available by Lucas in 1960s they sold hundreds of kits to private owners who had 6 v electrics. They even produced a 2 page booklet for it.
All you need to do is on 6v is swap the two non earth wires over and fit a Zener with heat sink, ang blow all your 6v bulbs out if you got to swap them for 12 v ones !
The 1964 Dommie wiring diagrams are shown with a zener diode attached directly to the supply side of the ammeter (alongside the horn)
These are the only two loads that don't go through the ammeter - Lucas were rightly concerned that it would burn out the delicate moving coil inside the ammeter itself.
This was 12 volt electrics, but the alternator stator was a three wire type - bringing in extra windings on the light switch
Lucas introduced the 2DS506 silicon rectifier as a replacement to the selenium rectifier (I think the part number was 47111) at the same time as introducing the zener.
All Commandos had a silicon rectifier, but the Dommies saw both, depending on the year.
These are the only two loads that don't go through the ammeter - Lucas were rightly concerned that it would burn out the delicate moving coil inside the ammeter itself.
This was 12 volt electrics, but the alternator stator was a three wire type - bringing in extra windings on the light switch
Lucas introduced the 2DS506 silicon rectifier as a replacement to the selenium rectifier (I think the part number was 47111) at the same time as introducing the zener.
All Commandos had a silicon rectifier, but the Dommies saw both, depending on the year.
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I assume you mean magneto ignition?
With the magneto providing the sparks, there's no load on the charging system at all once the battery is fully charged so the Zener diode would have to cope with the full alternator output when the lights were not in use if the stator was connected for full output.
To prevent the possibility of the Zener being overloaded when the lights are off (or 'L'/pilot switch position is selected) only white/green and green/black outputs go to the rectifier. Green/yellow is isolated until the main lights are switched on ('H') as the lighting switch also connects green/yellow (5) to green/black (5-6-7) so full alternator output then goes to the rectifier.
I don't think you are referring to the right diagram.
Last edited:
Yes, i was referring to this diagram:
The use of a zener here, I believe preceded the 650ss/Manxman/Atlas layout by nearly a year.
Notice also the remark describing how the zener was moved to the other side of the ammeter later on.
I have never actually seen that - any later wiring I seen was as per your diagram where the zener was hung off the rectifier.
The use of a zener here, I believe preceded the 650ss/Manxman/Atlas layout by nearly a year.
Notice also the remark describing how the zener was moved to the other side of the ammeter later on.
I have never actually seen that - any later wiring I seen was as per your diagram where the zener was hung off the rectifier.
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hello now both these harness wiring diagram are WORNG as they use the later or after 1964 SA 88 lighting switch are AS the Norton Manxman1961/2 And home model late1961to62 650ss used the SA41 lighting switch and the early wiring diagram And all Haynes manuals show the wrong diagrams for wrong Norton twins model years and any of you can argue with me to the cows come home as I own these bikes and rebuilt them as well
