Testing voltage with multimeter - high current warning?

Whenever I test an arduino that's connected via USB with multimeter I get a high current warning in Windows and sometimes it incapacitates the USB (not sure if temporarily or permanently, need to check after restart the condition of the USB)...

Why would testing voltage with multimeter cause high current warning? It might have been high voltage warning, not sure if I remember it right.

-Val

Without know where exactly you had the multimeter leads connected I'll guess that either you have shorted a couple of pins or you have the multimeter on current mode instead of voltage. That makes it effectively a dead short across whatever you're trying to measure.

Steve

Right. That shouldn't happen unless you are measuring current (Amps) incorrectly. That's why most multimeters have a separate current-probe connection... So you don't accidently switch to measuring current and short something out.

If you get excess current when measuring voltage, something's wrong!

Nothing bad should terrible should when measuring resistance either, but you won't get accurate resistance readings with the circuit powered-up and you might cause a temporary circuit malfunction.

...If you want to measure current, you have to break the circuit and insert the meter in series - [u]How to measure current with a multimeter[/u][/color][/url].
Current measurement is kind of a pain, and it's "dangerous" because you can burn-out something or burn-out the fuse inside the meter. I work in electronics and I measure voltage and resistance "every day", but I can't remember the last time I measured current with a meter. My bench power supplies at work have voltage & current meters built-in so I do keep an eye on it. At home with my electronics hobby, I usually estimate or calculate current.

DVDdoug:
Right. That shouldn't happen unless you are measuring current (Amps) incorrectly. That's why most multimeters have a separate current-probe connection.

Only on the high (10 A) current range.