Ok, now we're fixing this thing and popping the cluster might be on the horizon. Easier than layin in the car at any age but I hear ya.

The cap across the vr isn't a ground route it's a filter for the vr clicking. Ground to cluster is still through that smoked connector, fix that and bobs yer uncle. Unplug the new fangled seat buzzer was a typical day 2 thing. Ya can melt a little plastic back in there but at least try heating it up and nudging it back. If committed to to adding a dedicated ground, flip ckt board over and solder a wire to that trace.

Dash pad is 5-6 screws (2 ends, 3 bottom) and 3 screws at defrost grille. Carrier is 3 screws across top and two at the bottom. Pull forward, 2 white clips hold harness to carrier.