Series 2 Smiths rev counter

[Montydog2]

The rev counter on my 1971 series 2 has suddenly stopped working and I wondered if anyone had had a similar problem? I assume there is a sensor on the ngine but have not been able to locate.

Any help would be appreciated.

Chris

[cactusman]

Think the series 2 cars have a current triggered tachometer where the current to the coil goes via the tachometer. Peer behind the tachometer. If there are two white wires looped through the back and a third green wire feeding power to the tachometer internals that is what you have. If the car runs ok check there is 12 volts at the green wire when the ignition is on. It is fed from fuse 7. If there is no supply there is your problem. If there is 12 volts and the car runs happily then there is an issue with the tachometer.

[wwayman]

If you take it apart you will find an electrolytic capacitor on the small circuit board. Replace the cap. This fixed mine.

[Bfastr]

look for this black capacitor and replace it.
I am trying to find my notes on the value I used. it was close to the original, a simple job to solder in a new one

[johnetype]

The original was 2.5uf. The modern day equivalent will be 2.2uf. Use a tantalum capacitor rated at 25 volts if you can get one and remember to keep the polarity the same way as the original.