Hi I got voltmeter gauge I can connect negative to bolt on the screen which goes into the frame but where can I fit live wire to only come on when I turn ignition on any instructions or pictures would be great I got round voltmeter and it fits lovely in handlebar York

Best to connect directly across the battery. Anywhere else will be compromised by the bike wiring system losses.

Hi magg do you mean just wire it to battery if I do this won’t it stay on when I turn ignition off

Yes, but a voltmeter should draw very little current, no more than 10 microamps. You should consult the specifications for the input resistance for your voltmeter.

I wired mine to a switch so it can turned on and off when not in use. Also worth adding an inline fuse just in case the positive wire was ever to short out on something.

Thanks for reply I’ve had the old voltmeter on the bike tested today with the engine not running I connected the multimeter to the live and negative wire on the back of voltmeter and it read 12.5 but on the led voltmeter it read 9.8 it seems to be 3V out would this mean the voltmeter is at fault because multimeter reading on the wires going into voltmeter read 12.5volts?

If you trust your multimeter then the "old" voltmeter is faulty.