Tachometer Question

[Sea'Scape]

I have a Mercruiser 4.3 V6 engine, 1997. The tachometer, a Faria gauge, has suddenly started reading high by about 50%.

The question I have is how to determine whether it is the gauge or the sending unit that is at fault. Or, could there be something else that might be causing the problem?

The gauge appears to move freely as I change engine speed, just reading high.

 

[dubs283]

Re: Tachometer Question

more than likely it is the guage, there are settings on some tachs for 4,6 or 8 cylinders but if you haven't messed with it that probably isn't the cause

you can disconnect the grey wire from the back of the guage and connect an analog shop tachometer to it to verify the wiring is good