Dash & dome light question

[DesertRat]

I have been tweaking the last bugs on my 67 Barracuda. I am left with non working dash and dome lights. I have checked power to all my glass fuses and they all are good and power both ends. The relevant fuse is the Inst. fuse which with ignition on and headlight switch dimmer full left gives full voltage to both ends of the fuse and when turned to the right the voltage drops per dimmer protocol. I am thinking grounding but I am unsure where to ground to. I bought a new headlight switch which has a tab that the original one does not have. Does the headlight switch have to ground for this to work. All the power is going where it is supposed to. I am stymied-------------

 

[grjammer]

The dome lights are powered waiting for a ground from the door switches. The dash lights are fed from the inst fuse to pin G on the round connector on the rally gauge circuit card, and the fuse is fed from your headlight switch. If your dash case is grounded to the dash frame and subsequently the body the dash lights should work. They get the ground through the bottom 2 screws on the rally dash. My 69 had 4 extra grounds from the P.O. added to the circuit cards...(not needed imo)

 

[DesertRat]

I ran an auxillary ground from the gauge cluster to my under-dash ground bar and I now have dash lights.
Nice to know it was grounding.