An ammeter displays amps and a voltmeter displays volts but they both work
the same way - by driving a current through the moving coil of an analogue
instrument, it is just in how they derive that current that they differ.
Using a voltmeter in place of a ground strap to measure leakage current is a
very effective way of detecting leakages smaller than a test-lamp would
reveal, and far safer for the instrument than by using one on an amp scale
only to find that the leak is far bigger than you thought and wrapping the
needle round the end-stop. The voltmeter will never read more than 12v no
matter how big the drain, and if it reads less than 12v it tells you that
the drain is small but nevertheless still there (like the surface leakage on
my batteries). It's just lateral thinking.
PaulH.
----- Original Message -----
From: <REwald9535@aol.com>
To: <economu@whidbey.com>; <mgs@autox.team.net>
Sent: Tuesday, May 02, 2000 10:35 PM
Subject: Re: Fw: Alternator Woes
> I've been quiet through this exchange, but I can't stand it any longer.
Voltage is electrical pressure NOT current flow. current flow makes
batteries go dead not voltage (pressure). Think if you had a leak from your
water pipes, I doubt that you would call your plumber and say that you had a
leak that had already leaked 50 PSI. More likely you would tell him that
the leak was so bad a five gallon bucket had already filled up (current)
> A much better and more practical way to find a current draw is to use a 12
test light between the battery cable and the battery post,
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