Reply To: Kill Switch for a ’57 Merc Mark 25

[frankr]

Wade, that is how it’s done.  However, your theory of how it works is only partially correct.  It is true that the closed set of points on the inactive cylinder provides a ground return.  But what you are mossing is that that closed set of points is paralleled by the primary winding of its related coil.  So the coil winding is also a ground return.  True, there is around an Ohm of resistance through that winding, but it still is an adequate ground to kill the active cylinder.