Yamaha Digital Gauges

My speedometer is reading some crazy readings. Shows I'm running 40 mph when boat is in garage. Have blown the hoses out and air is coming through to the foot strong. When blown towards gauge the speed decreases to about 20. Seems like something may be clogged between there and the gauge. The gauge is a real pain to get to the back of but that is all I know to try.

Just bought the boat from a friend and he said it was working before it was taken to dealer To have a new powerhead put on. I picked it up and went to perform breakin and it was not working. I know dealer put a hours on it so it may have happened then. Also I had to take it back to have them switch some wires around that they had hooked up backwards to get the trim gauge to work.

Any suggestions??

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