Dash light grounding question

[rvanstory]

I'm going to publicly display my limited electrical understanding with this question.

My gauge lights will not light up when the headlight switch is turned on. I have checked continuity to the 12v+ and the ground leads and the fuse as well as bench tested the lights independently of the switch (direct ground and 12v). On the light switch drawing, it shows a "interior light ground" that's not part of the switch, nor is there another ground wire coming out of the harness. Nor can I find a ground wire labeled specifically for interior lights (they are currently grounded to one of the other dash harness ground leads). I did ground the other "ground" wire (top of picture) to the chassis. Wondering if I'm missing something about this "interior light ground" pictured in attachment. If I'm to ground the switch to the chassis, there are no spade connectors for that.

Any insights would be appreciated.

C13602DB-5032-4E47-9F5E-604D553AB0F4_1_201_a.jpg

[JJK]

The interior ground connector allows the interior lights to turn on when the knob is twisted counter-clockwise all the way, you will feel a notch. It essentially closes the ground circuit. If the knob is twisted all the way clockwise, the gauge lights will not turn on. Check if you have the knob twisted correctly to turn on the gauge lights.

[Dave M]

I think you may be confusing interior lights with dash light. Two different things. Old school head light switches have a potentiometer in them that varies the brightness of the dash lights. Then when turned all the way in one direction it clicks an interior curtesy light switch. Not sure if that’s what you’re working with though.