Ok, I have looked at the schematics in the Barracuda supplemental info and in the 1967 Plymouth service manual. Both show the top switch to the motor, but neither shows how the power gets to the top switch. In addition to that, I have searched FABO for input.
FABO had the most info, and the consensus is that the top switch wire attaches to the “RED” post of the ammeter, as mine was when I pulled the dash out.
Finally, there is no where else on the back of the instrument panel that could accommodate the top wire.
Thanks to everyone for input.