Have question about ignition box install

[str8stang036]

I have a Mallory Hyfire VI ignition box ready for install, but I have a couple of questions. It has an RPM switch output. Does that go connected to the RPM instrument panel? Which wire does this connect to bck there?

 

[bmorrisj]

i think thats for an aftermarket tach, thats the rpm sigal wire for it...

 

[RobbMc]

I have a Mallory Hyfire VI ignition box ready for install, but I have a couple of questions. It has an RPM switch output. Does that go connected to the RPM instrument panel? Which wire does this connect to bck there?

That wire completes a ground when you hit a selected rpm. You use it when you want some electrical device (such as nitrous solenoid) to activate at a selected rpm. Below the selected rpm the wire is an open circuit.