So first off, I'm Jim. I'm a computer geek at my core and have been pretty much since I could walk.
I'm a systems administrator by day (and often by night as well) with cars, electronics, photography, and all of that mixed in together as my hobbies.
With that out of my way, I decided to throw up a quick post about what happens when you use cheap multimeters...and more specifically, what happens when you use them incorrectly.
I happen to have a quite cheap ($30 us or so?) RadioShack meter that I just use for dirty stuff especially when I'm working on my cars as it doesn't need to be all that accurate.
Anyhow, with a recent rash of dead batteries in one of my cars, I decided to probe each fuse without the key in the ignition to see which circuit was drawing power. I set my meter to current measure mode. After getting some weird results that didn't make any sense (43 milliamps across the main battery circuit even with the car running); I decided to see what my battery voltage was...well, I forgot to set the meter to voltage mode.
As you can guess, I was found that out when the huge spark I got when I touched to probes to my battery terminals scared the crap outta me.
My meter says it's cat 3 rated...not sure if I believe that or not, but nothing blew up and I didn't get fried; so it ended fine.
The main lesson here? When working with cheap tools,
ALWAYS double-check your mode selector dial.