Wire for digital volt meter

I have installed a digital volt meter to at least know in advance when the dreaded stator/rectifier issue arises. I made a small bracket that attaches to one of the forward bolts holding the gas tank. I certainly don't want to wire direct to the battery as it would be "on" all the time. Any clue as to a hot lead I can tap into that is only energized when the ignition is on? Thanks in advance!

 

I used the license plate light lead. This way if there was an issue, it's just the license plate light and not my rear brake light lead.

 

BTW, I am using a power controller which gives me options for both, always live and switched outlets. However, taking into account if don't use a power controller, you can do the same with a 12v relay. I used the power lead directly from the battery and used the ground as the switched leg on the relay. This way the 12v + voltage to the meter is direct and not running through any other circuit or wire path. If you don't have familiarity with what I'm talking about, I'll see if I can find the drawing I did.

 

Until you forget to turn off the switch...

That's one of the reasons I went with the power controller, although itonically it's parasitic draw is probably the same as a meter, but the meter I have also has a back light which would draw a bit more juice than a meter itself. I setup the power controller to work with a momentary switch so that I can press a button, get the reading on the meter and release the button. When the ignition triggers it applies constant voltage on that same circuit, thus allowing no key monitoring, active monitor while the bike is on and no worrying about forgeting to flip a switch when I turn the bike off. Technically the same can be done with a relay I believe, where by adding a momentary switch to trigger the relay in addition the the switched circuit.

 

Thanks for all the replies. I went with a direct plug in to the battery that can be disconnected when I am not riding. Using the same 2 prong flat plug that I use for the battery tender. That way the display of volts is always on when I am riding.