I want to install a 12V digital volt meter

[ewarnerusa]

I wanted to install a digital LCD volt meter with LED backlight display that I bought off amazon. I'm familiar and comfortable with 12V electrical and I have decided to just tie into a 12V connection from behind the existing control center (where the tank/battery gauges are, water pump switch, water heater switch, etc.). I'm going to mount the volt meter above the control center. While the LED backlight would draw very little juice, I figured I'd want a way to switch it off to avoid any unnecessary parasitic loads. My plan is to wire up a switch that will turn the volt meter display on and off. I snooped around with my multimeter and there are many different wires carrying the 12V signal to choose from. My plan was to pick a favorite and tie the switch into it, then hook the meter to the switch.
Anyone have any comments or suggestions for my idea? Thanks.

[DrewE]

What you suggest would generally work fine and be simple enough. You would be measuring the voltage at your control center, which may not be exactly the voltage at the battery.

If your voltmeter has separate power and sense lines, you can get a more accurate reading of the battery voltage by connecting the sense lines directly to the battery connections (with an appropriate small fuse in the positive line) and just switching the power line on and off for the meter. The meter itself doesn't use much power at so circuit capacity for powering it shouldn't be a big concern.

The sense lines don't need to be heavy wire from an electrical point of view; they don't carry any appreciable current at all, only a few microamps. They should, of course, be heavy enough to be avoid breaking mechanically.

[CA_Traveler]

It will be a lot better than the standard idiot lights.