I don't think the MSD window switches supply a voltage, just a switched ground signal. You'll need to figure out how to wire this to the Zex controller. Is the arming switch for the Zex setup a switched ground? If so then you could wire the RPM window switch in series with your arming switch. Dave >resource? so i would want one for activation(need to >deliver 5.0 volts) at 3000 RPM and a kill for around