What's Going on with Tach?

[zonaman]

Here's what the tach is doing on my '95 Tracker 90 hp. Any ideas on what it is and what the cure might be?
Thanks.

 

[Chris1956]

Gee, is that with the key off? Motor running? idle speed? full speed?

Tach should zero with key on and motor not running. They need ign voltage and ground, plus a stator signal to work properly. I suggest you check your wiring.

 

[zonaman]

First thing I checked. It looks to be wired properly. That is underway around 3000 rpm, swings to zero.

 

[gm280]

Even though the tach seems to be wired correctly to offer any reading, I too suggest you REALLY check the voltage and ground wires going to the tach, AND the signal wire from the engine itself. So many times a corroded connection offers proper voltage readings until vibration gets going. So first thing to do is trace the tach wires to their source(s) and remove, clean to shiny metal and reattach those wires. Then see how that works. You maybe surprised...

If then you still have an issue, come back and tell us. There could be other issues inside that tach itself or even with the signal source. JMHO

 

[GA_Boater]

So the gas gauge is acting normally? :facepalm:

What about the other gauges?

You have either a loose or corroded connection or connector. It could be either the voltage feed or a ground. With the key on, reach under the dash and start wiggling wires while watching the gas gauge.

Voltage and ground for gauges is often piggy-backed from gauge to gauge. If some gauges work normally, check the piggy-backs to the next gauge.

 

[zonaman]

The gas gauge was reacting to the float bobbing up and down on half a tank and a good chop. It settles down on an even keel.

 

[GA_Boater]

Other gauges?

 

[zonaman]

Thanks for replies. Volt meter OK, Speedo has no pitot, but sonar reads S.O.W. so I'm not worried about it. All lights on gauges work.