It's a Bendix S4LN-21. Trying to understand where the inner wire is connected as well as the outer shield wire. I'm guessing one goes to what appears to be a capacitor? Which one? And where does the other one go?

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Center wire (conductor called the "P" lead) from condenser to switch. Shielding to ground at mag and you can use the shielding at the switch as a ground for the mag. Or ground the shielding inside the cockpit an run a separate ground for the switch. Hope I've explained it clearly.


Someone correct me if I'm wrong, but I believe the shield should only be grounded at one end, usually somewhere on the body of the magneto.The capacitor is for noise suppression. 

The center conductor goes to the mag switch and it must be wired to go to ground when the magneto is to be disabled.


I ground the shielding at the mag an use the shielding at the switch for ground. The capasator is to prevent the mag points from arching, without it the points will fail quickly.



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