Best Way To Wire A Voltmeter?

How about the switched live/ output side of the kill switch?

 

I would put it on the ignition coil feed myself. If you put it on the kill switch and then shut the bike down with the ignition switch, it would still be on. I never use the kill switch except when I am working on the bike and want to make sure all curcuits are dead. ...J.D.

 

Across the battery with a fuse. Accurate readings where it counts. No worries that it is "ON" all the time, as voltage metering has a very high resistance.

 

Switched constant live that way you will get an average system reading and it will reflect the charge rate when the engine is running.

 

I'll apologise in advance that this is not a direct answer to your question, but, have you thought of an alternative like the products from here :-

http://www.sparkbright.co.uk/sparkbright-eclipse-battery-voltage-monitor.php

I've bought a couple of these for fitting to 2 (Gen.1) Street Triples - the charging system on these bikes is famously 'fragile'! They connect direct to the battery terminals, have very low power draw and can act like an alarm indicator by flashing when the ignition is off - though I notice the latter function is not promoted on the web site. They look very discreet, the lead lengths can be customised for your application and the guy that makes them is amazingly helpful.

Worth a thought?

 

Couldn't you piggy back off the live terminal of any ignition switched relay .... fuel pump, perhaps? Save the cost of a relay.

 

Kind of depends on what you want to achieve by fitting one as unlike an ammeter no matter where you fit it it will also show the system load and charge so it you turn on the light when the engine is running you will initially see a drop followed by a rise as the alternator/regulator try and keep up with the drain same goes for a rise in RPM as the system is self regulating.

 

I've got a switched relay unit on mine with 3 outputs. I use 1 for a sparkbright eclipse, 1 for a usb plug in the glovebox and 1 for my sat nav.

I use the front brake light switch as the switched live to the relay.

It works a treat and the sparkbright gave me a warning that the charging system wasn't working properly which turn out to the stator plug starting to melt.

 

It takes it from the relay unit. The unit is wired directly to the battery with a switched input from the front brake switch so it comes live when the ignition is turned on.