I have the same issue. I have soldered all ground wires and still the same thing. It does start working evry now and then without reason but then goes back to this same state. All grounds are soldered to a 10 ga wire in separate locations. The wire is ran to the block. I recalibrated once and it worked for a while then it went back to doing the same thing. I am running the 12v power source on a toggle switch rather than a switched 12v souce.