How much current does a volt meter draw?

[Hoyt Clagwell]

Over the winter I installed an old style analog volt meter. It was a replica from and old John Deere. I thought that I tapped into a switched lead but I guess I mistakenly used a hot lead as the meter is working all the time even with ignition off. It will be a big pain in the ask me where to change it and I'd like to put that off for awhile. Will the volt meter drain my battery quickly or will it go from week to week without an issue?

[s8ilver]

I know electronic voltmeters are designed to draw as little as possible, as drawing a larger current would affect the voltage you're trying to measure. Analog? More. How much more? No idea. Measure your battery voltage drop over a certain span and extrapolate?

[Muzz258]

A good old fashioned analogue volt meter will draw around 1-2 mA. As your Z3's residual draw is around 40 mA, you will not notice any issues

If it's a digital volt meter, then that's a different story. Depending on the meter it may draw between 15 to 30 mA. That is enough to give you problems.

[s8ilver]

I can see how our last two responses will sound contradictory. What I meant by "electronic" is a handheld meter with its own power supply. It'd designed to draw so very little as to not affect the measurement. And yes, a digital voltmeter that runs off the car's electrical system will draw far more than an analog meter (at rest), unless it was battery powered or something.

How do the M (and FL Z) analog clocks run? Do they draw continuous power, or does the clock have a mainspring that gets wound? I don't think I've ever looked at one after I pulled it out of the car to see if it kept time for a while.

[Hoyt Clagwell]

That's great. It's an old fashioned analog gauge so it shouldn't cause me any trouble. If I ever decide to remove the console again I will try to get it tapped into switched lead just so it kooks better.

I'd have to check but I did notice in passing that the OEM "analog" clock was included in one of the Bentley manual's wiring diagrams so I'm assuming that it is some kind of quartz movement that needs a bit of power to run as opposed to a mechanical mechanism.

[IndianaRoadster]

Just keep a battery tender on it when not driving it for awhile.