Anyone know what wire powers bulbs in the dash?

I’ve got an 06 megacab. The dash backlights and climate control backlights don’t work. Everything else is fine including the rear lights. I’ve tried everything. Checked and replaced all fuses. Checked the wiring into the fuse box, and all pigtails for any burned wires or connections. Checked grounds. Replaced the headlight switch. Even pulled the cluster and tested each bulb individually (all were fine). I’m to the point now that it has to be a wire issue at an unreachable area. So my thought is find the wire At the connector that is meant to power the bulbs and splice it into the headlight wire.

So does anyone know which wires are for the headlight and backlights for the dash? Or have any other ideas?