Shift Indicator Lights

My street rod has a six wire shift light, but is powered thru the shift unit like your old 8 wire indicator.

If you only have six shift indicator wires, what are you checking continuity from if there's no power input line? Maybe this new unit works opposite of the old unit.  Instead of sending power to each light, maybe the unit regulates the ground for each light instead? That would explain no power source to the shift indicator on the trans. If you supply ignition source power to each shift indicator light(actually hook all of the lights to one ignition source power feed), then hook the ground wires from each light to its corresponding wire on the shift indicator on the trans, the indicator would ground the appropriate light as the shift indicator is moved thru the gear ranges? Is that possible?

Don