question Centurion tachometer

[Aussie]

The tachometer on the cent isn't working. It's apparently just a simple voltmeter that runs off a tachometer generator on the front of the B (right) bank of the Meteor. I've read the manuals and know where it's supposed to be but haven't spotted it yet - will see if I can remove a bulk head plate to find it so I can test it.

I suspect it's just a loose connection and the tachometer is a lot easier to get at, so plan to start at that end and make sure the tachometer is working.

So my question is, how do I test it? I guess connecting the terminal to a battery would do the job but not sure what voltage would be OK without damaging it. A car battery seems a bit over engineered and not sure if that would be safe.

Cheers

James