On Wed, 27 Jun 2007 13:09:26 -0700, beerismygas
wrote:

i want to see if a short is causing a drain on my car battery.

i have a digital multimeter. one way i theorized was to connect it in
series with the battery via the earth lead and negative terminal.


is this logic sound? or will i fry my multimeter? is there any other
way to find a short (apart from scraping the earth lead to the neg
terminal to see if it arcs - which on my car it doesnt)

thx


My battery was dead if I didn't drive it every 16 or 24 hours, I
forget which. So when I went away for Thanksgiving, I disconnected
one side of the battery, and the battery was still able to start the
car when I got back 3 1/2 days later. So I was using too much current
when the car was off. (I already knew the battery was charging
propertly.)

If using s light bulb to find a short, Pat Voss (the smartest car guy
I know (via the radio)) recommended a #53, I believe it is. The guy
has lots of meters, but I got the idea he thought a lightbulb was the
easiest way. A 53 should be a bayonet mount, with the outer ground
and one center contact, and a spherical glass not much bigger than a
1/4 inch. Used for dashboard illumination and little things like
that. If a 53 doesn't look that, it's possible I got the number
wrong. Get back to me. Delete nopsam.

I expect this will be in the self-service part of a consumer autoparts
store, but there are so many new bulbs in the last 20 years that maybe
not everywhere

It worked for me when I had an extra alarm accessory that ran all the
time that was running down my battery. The bulb glowed then, but not
after I removed the accessory. The clock in the radio is not enough
to light a 53. Of course I already suspected the burglar alarm, and
just didn't realize the beeper transmitter in that particular case
used power all the time, not just when it waa alarming.

I see it was probably the belt. That's actually the first thing to
check. EVen if they are not dirty, they stretch with age. Even if
they are dirty, you can probably just tighten the belt.

Ihaven't read the rest of the thread, but I'm sure they told you about
removing the battery from the circuit and using the ohmmeter part of
the meter. You should make sure the voltage of the ohmeter is in the
same direction as the car battery.


You didn't say what year or make or model of car. You should have.
Late in the thread we find out that it has no powersteering. So it's
not the typical car everyone was thinking of, but even if it were
typical, you should give this kind of info.

If you are inclined to email me
for some reason, remove NOPSAM :-)