Mopar Muscle Association UK

Bought a cheap jobbie off the bay but does not work,what am I doing wrong?.
Red wire to live, Black wire to earth, Green wire (signal wire) to - of coil and doesn't work tried Green to rev counter wire no go please.
Cheers Bryan.

You take a feed from the negative on the coil don't you? That should be where your rev gauge gets its reading from if you have electric ignition...

Assume it works off the same feed then you set the RPM you want it to indicate a shift at?

(above might be wrong )