tach stops at 1000 when motor cut off

[RLT III]

when you turn off motor the tach stays at 1000 and then when you turn the ing back on it drops back to 0..... Why is this happening and what should i do to fix it?

 

[Silvertip]

Re: tach stops at 1000 when motor cut off

There is no need to attempt fixing something that isn't broken but will be if you try to fix it. In other words -- keep your hands off of it because it is working normally. Most gauges these days are designed to "float" and the needles may or may not return to zero or their regular position unless powered. Speedometers are strictly mechanical for example and are indeed malfunctioning if they stop anywhere other than zero when the boat is stopped.

 

[RLT III]

Re: tach stops at 1000 when motor cut off

Thanks for the answer... your response's are always so pleasant Silvertip

 

[jhebert]

Re: tach stops at 1000 when motor cut off

To explain in more detail:

When no current flows in a meter, the dial pointer returns to the position that represents no current flow. In the case of most meters this usually also corresponds to a zero position on the dial scale. It is also fairly normal that a meter zero position occurs at the extreme of the pointer movement. In the case of a tachometer, neither of these assumptions is true. The zero-RPM scale mark on the tachometer is not coincident with zero current flow. And the zero current flow position is not coincident with the extreme of the pointer movement. The tachometer zero or rest position usually corresponds to about 1,000-RPM on the scale. This is the zero current position. When the meter is operating and indicating below 1,000-RPM the current flow in the meter is actually slightly negative.