At 07:00 PM 8/7/2009, Courtney Hook wrote...
>OK, I've been through the archives (which I suck at) to find this
>info, but can't find it. How do I set my multimeter up to check for a
>current draw.

First, most meters have separate jacks for volts and amps, you're
always safe measuring volts, but if you're measuring amps and put the
leads across a strong current source (like the battery), you may blow a
fuse in the meter.

When measuring either volts or amps, always start at the highest range,
and work your way down. Some meters have separate jacks for amps and
milliamps (mA - 1/1000's of an amp). Start with amps, and if you don't
get a reading at the lowest amp range, move down to milliamps.

If you're trying to find why something isn't working, and suspect a
blown fuse, turn that something on, and measure volts across the
suspect fuse. If the fuse is blown, you'll get a reading. If the fuse
is good, you'll get 0 volts. You could also get 0 if a fuse in the
device is blown (such as a radio with it's own fuse).

Typical meters will only measure a relatively low current (up to maybe
10 amps). Don't try to measure amps on something which is turned on,
unless you know it draws less than the meter can handle.

If you just want to see how much current is being drawn from the
battery when everything is "off," disconnect the battery ground
connection, then measure amps between the removed ground and the
battery's ground post.

If you've got something draining the battery, and want to find out
what, pull the fuses one at a time, and measure amps across where the
fuse was. The current will go through the meter and you'll see how much
current that circuit draws.

A radio (when "off") or clock might draw something on the order of 10
mA.