what is this part ?

does anyone know what this is called or it does ?

it is on the back of a 71/73 speedometer cluster, it is on both the tach and non tach version.....

the reason i ask, is because i am dealing with some wiring issues with the changover, and am trying to determine if i have things wired wrong, or if this part is not doing what it is supposed to do..

thanks

thanks,

so it would somehow have been connected to the factory gauges that are in the center console??

the reason i ask, is because there are no gauges, per se, in the speedo cluster.....only::

turn signals
hi-beam
brakes
backlights
gas gauge