OK, this question comes from working on a Seagrave V-12 engine, but I think it may still apply to Chevys, so I'm throwing it out there. AND, it's driving me nuts trying to figure out.
Setting the timing on this V-12. HUGE distributor with TWO rotors in it, 2 sets of points, 2 condensors, and 2 coils. Set up like 2 six-cylinder engines running side-by-side.
Anyway, my chosen method of setting static timing is to use my continuity tester tone on my MultiMeter. I hook one side up to the hot wire, either at the coil or the distributor, and the other to ground. Then, turning the distributor, I find the point when the tone just goes out, indicating points just opening.
At least, that's how I THOUGHT I did it. This time, I got tone even when the points were CLEARLY open. The ignition switch was definately off. This being a fire truck, there are 2 ignition sets, so I had 4 sets of points to try this on. It was unanimous.
Took one of the distributors out of the truck, and set the points in the vice, with the continuity tester - no problem. So HOW is the coil primary grounded with the ignition off?
Are the primary and secondary windings in the coil by necessity connected, at least enough to get continuity? Or am I missing something? I thought it was the breaking of the primary current that triggered the secondary, so how is it triggered if there's always continuity?
Matter of resistance?! Somebody educated me . . .
-Michael
