On Apr 25, 3:55*pm, "Leo Lichtman" wrote:
"DanG" wroteI've always been taught to put a test light between the negative lead and the negative post. *Do your same fuse study. *If the light is
burning, something is on.

^^^^^^^^^^^^^^^^^^^^
It's not an electrical reason--it has to do with safety. *Having the ground
cable dangling in the engine compartment poses no risk of a short (to
ground.) *However, I consider an ammeter much better than a light bulb.
It's going to be in series with whatever is draining the battery, which
could cut down the current to a level that doesn't light the bulb. *If you
do use a light bulb, use the lowest wattage you can find. *Possibly even a
6v bulb in a 12v system.

You connect both in series and the bulb protects the meter from a
short or heavy load. The 10A range on the $4 HF meter reads down to
10mA, so it and a headlight bulb should be enough.

jsw