Do the individual bulb sockets ground to the instrument panel itself, or is there a separate ground wire in the instrument panel harness that grounds to another location? There's only one wire coming from each bulb socket so I'm assuming the socket grounds itself???

 

The single wire sockets do ground themselves while the double wire use their own power or ground.

 

The metal backing plate serves at the ground for the bulbs. This was a hurdle I had to deal with when I created my own instrument cluster. The bulbs in the new gauges had ground wires but the turn signals, brake warning light, high beam didn't. I soldered a ground wire to the sockets that hold each light in place, then ran those wires to the dash frame.

 

good idea.........thanks!