Speedo not working

[nautiboat]

Can someone point me to the trouble shoot procedure for Speedo not working? I have blown air thru the tube? What is next? How can I confirm the trouble is not the guage? 1989 SN2001. Left side no read out, right side reads fast. Thanks!

[east tx skier]

Get a safety pin or smaller or a small dental drill bit and dig out the pitot pickup. Blowing the lines doesn't always get the job done. If that doesn't do it, I give up.

[DanielC]

Your speedometer is a pressure gauge, a hose, and a pitot tube.
(A pitot tube is just a forward facing hole, that has pressure built up in it when it is moved forward.)

The gauge does not work.
The hose is unplugged from the gauge, or somewhere else in the boat, or from the pitot tube.
The pitot tube is plugged.
Those are your possibilities.

If you are testing the gauge, do not put more than about 10 psi on it. if you use full pressure from an air compressor on the gauge, you will damage it.

More info here.
http://www.airguide.com.au/index.php?p=1_1

[nautiboat]

speedos

Your speedometer is a pressure gauge, a hose, and a pitot tube.
(A pitot tube is just a forward facing hole, that has pressure built up in it when it is moved forward.)

The gauge does not work.
The hose is unplugged from the gauge, or somewhere else in the boat, or from the pitot tube.
The pitot tube is plugged.
Those are your possibilities.

If you are testing the gauge, do not put more than about 10 psi on it. if you use full pressure from an air compressor on the gauge, you will damage it.

More info here.
http://www.airguide.com.au/index.php?p=1_1

Thanks DanielC, that is just what I was looking for.