Flicker· Premium Member
Discussion Starter · #41 ·
Might be a bit late for you but Norton Owners Club of NSW - How to Rebuild a Lucas ignition Switch to Better than New
Tip I was given years ago by another high-mileage T160 owner (same switch) is to drill a small hole in the terminals end at what's the lowest point when the switch is mounted, any water that does get in will drain straight out instead of swilling around corroding the contacts.
There are also some parts that'll make it more waterproof:-
. When Norton fitted the switch on Commandos, they fitted a boot over the terminals end - 06-4891 or 06-5723.
. '81-on twins covered the key end of the switch with a clip-over cap - 60-7335, corresponding switch securing "Nut" is 97-7120.
. T160, '79/'80 twins "Cover" is 60-4335, corresponding "Nut" is 97-4589.
Mmmm ... sort-of ...
The Zener shouldn't "conduct" at all 'til the DC system reaches a little under 13V. You might be able measure "battery voltage across zener terminal and earth" but, engine not running, the two sides of the Zener circuit won't be connected.
Otoh, "10 volts and falling" meant the Zener was conducting, although the engine wasn't running - ultimate worst-case, the Zener conducts without any resistance and the fuse blows.
I appreciate the suggestions and I was thinking to myself "Surely there must be some switch out there better than this one"
I tested the Zener diode in an isolated circuit and it holds 13 volts from my battery direct.
So I’m attributing the voltage drop observed in first test to be caused by the intermittent short in the old wiring harness.
And the short must be something like the insulation being rubbed very thin for my fuse not to have blown
With that, I’ll go back to the original electronic components for now and leave the Podtronics for when I might need it.
Also, with the original components in place, I'll have a clear-cut landing point for each terminal on the new harness.