About a year ago, I installed one of the electronic "gizmos" in the instrument panel of my 1971 D300. It replaced the steel strip inside the fuel gauge, which I deactivated, that reduced the 12V down to about 5v for the gauges. The new electronic device worked fine. About a month ago, I looked at the gauges while coming home from a about a 100 mile trip, and I had NO oil pressure. then I noticed none of the gauges except the alt., was working. The gauges came back on in a few minutes. but this on/off thing went on during a few more short trips, then stopped completely -dead. I pulled the cluster out and soon found I had a bad 12v connection to the new electronic device. Repaired that and the device was sending out about 5v in flashes as it should. BUT no working gauges as before, If i ground the 3 gauges (fuel/temp/oil press.) they move. SO what should I check next?? What have I overlooked. Thanks R