1978 85hp tach not working

[papaduck]

I purchased a 1978 Johnson 85 hp and the tach does not work. Is there a way to check the signal from the alternator or a way to test the gauge? I don't want to waste the money on a new gauge if there is no signal to the gauge.

[boats.net]

I am uncertain of the test proceedure and do not have the service manual for that model.

[papaduck]

Thanks for the reply.

I found the poblem. The sending wire was broken at the remote control.