I had an interesting snag the other day, the left-hand fuel gauge was intermittently showing zero fuel while at altitude. When the airplane came back down and landed, the problem went away. Now, this snag had been looked into several times previously, with no ability to duplicate what the pilots were complaining about. There seemed to be an electrical gremlin in the aircraft, and someone needed to put an end to it! After searching for an electrical related problem I think I found what was wrong…..
The wires on the back of the fuel gauge plug were frayed a bit, my hypothesis is that the cold temperatures at altitude, mixed with engine vibrations, were causing these frayed wires to ground on the case, or more likely to each other. So I re-soldered all of the wires into the plugs and insulated each of them individually. No problems have been reported as of yet, and time will tell if this was a complete fix.