Has anyone ever taken one of these apart? Do they have electronic components in them such as transistors, resistors, capacitors etc etc???

Mine won't read much above 1000 RPM no matter how high the engine speed is increased.

Glenn

Glen,

only mechanical item in tach is probably needle with its shaft. Rev counter takes its signal from ignition coil via ballast resistor. I'd suspect ballast resistor losing. Of course, check wire(s) first.

With ground faults the rev counter tends to do all kinds of weird movements as well. How's the alternator voltage?

Kalev

Since writing my query, I removed my rev counter and took the back off. As it turns out, there is a small PCB inside with a few electronic components. One of the components, an electrolytic capacitor, was all dried up. I replaced it and now my rev counter works just like new.

Thank you for your suggestions. Glenn USA