I have a '70 RR, rallye dash. Same thing. I pulled the whole rallye dash out. I took an old AC cell phone charger, 3.5 volts, cut the end off, and split the two wires. Touched the wires to the posts on the back of the gauge, and it worked fine. I took 800 grit sand paper, and gently cleaned up the curcuit board. All of my gauges and lights worked. Pain in the ace to pull the dash, but worth every penny I saved by doing it! Good Luck.