Have an issue with my display switching back and forth from mph to kph. tried to rework the connection and board with the power supply. then tried the same thing with three other junkyard power supplies and I still have the issue. I'm starting to think it might be the display itself. Does anyone know if there is a board on the dash itself that I need to resauter? I know it doesn't take much to take it out and look, but if someone has done this before that might be helpful. 1986 300zx digital display.