[trib]

I'm well into wiring my 6A and one of the things I do whenever possible, is test the functionality of the circuit as I wire it. My approach is the general Nuchols Z-11 figure. The mag switch is wired as shown, with the P lead using a shielded wire with the shield hooked up to the mag ground terminal and center wire to the P-lead, both going to the same switch. The switch is not grounded in any other way (recently discussed here), such that when the switch is "on" the P-lead is grounded to the mag ground terminal and ungrounded when the switch is off.

After wiring the system in this manner, I checked the continuity between the P-lead and ground terminal with the switch "on". Perfect continuity was indicated, as expected. I then placed the switch in the "off" position, expecting to see an open circuit (inf resistance), put continuity was still indicated. I disconnected the wire from the P-lead and checked the switch, and it functioned as expected. Continuity existed between the P-lead and switch in the "on" position, and in the "off" position the circuit was open. I checked for continuity between the P-lead and ground on the mag, and it was there.

Can anyone explain why this is so? This is a non-impulse slick mag. Does the continuity change at some point during rotation- i.e. sometimes grounded, sometimes not depending on angular position?

 

[elippse]

Right! Your ignition switch is in parallel with the points, so if they are closed, you will see a short. Basically the switch keeps the points closed. Rotate the engine somewhat, with the distributor caps off so that the engine doesn't start, and the short will go away.