Someone's home but the lights aren't on...

Here's the deal..
'72 Dart Instrument cluster issue

-Copper runs are clean, bulb sockets are clean, bulbs are good, Voltage Reg is new, all ohm and continuity checks passed.
-Main dash harness connector is clean and tight, continuity from connector ends to farthest end of copper run is good.
-Circuit board to metal cluster body screws to steering column have continuity, indicating good ground.
-Turn signal indicators work.
-High Beam indicator works.
-Oil Pressure warning indicator light works.
-Parking Brake light works.


-Instrument illumination lights DO NOT WORK.

Ideas?