Taillight/Cluster Backlighting Failure

[rhythm629]

When it started getting dark last night, I put my headlights on and got this error:


As it gets darker I realize my cluster backlighting is off (the gauges were red but the white #s were off)

I arrive at my destination and check the outside lights. The driver side taillight is out, the blinker works but the other 2 bulbs don't. I'm guessing it's not the bulbs since everything failed at once. Is it the fuse? or this ground connector:



And how do I find the instrument cluster backlighting wire in this diagram.

[rhythm629]

All three driverside running tailights are out. When brake lights are on, the bulbs work again, except for the smaller side light (which is not burnt out)

I've ruled out bulbs and fuses. Where are the ground connections?