As has been said 16mA is quite small, I have just gone through this process
on my daughter's car eliminating drains and bad charging before demanding a
replacement for the 15-month old, 3-year guaranteed battery.
My daughters car has an alarm and drains about 15mA with that not set and
about 35mA with it set. A good battery should be able to hold this for a
couple of weeks at least.
When looking for (as opposed to measuring) drains I don't use an ammeter as
that offers a very low impedance path and inadvertently shorting something
out when pulling connectors could damage the meter or its leads. I use an
analogue meter on its 12v scale, connected in place of the battery ground
strap, and if this shows 12v (with a charged battery) you have a drain.
Alternator diodes should have a very low leakage and with the typical
impedance of an analogue voltmeter will only show a few volts, not 12v.
Unplugging this should drop the reading to zero, and if it *was* showing 12v
before then one or more of the alternator diodes is bad. Incidentally a
dynamo/generator and control box should have zero leakage.
After that I would remove the purple fuse to eliminate interior lights,
horns etc, and any permanently powered circuit connected to it like a clock
or radio. Note that many radios have need a permanent supply for the
memory, and alarms are also often permanently connected. However all these
should be in the low milli-amps or less.
After that I would disconnect the hazard flasher in-line fuse (when you have
found it).
Then I would disconnect the browns at the solenoid to prove the leak onto
the brown wires on the one hand, or the solenoid or battery cable on the
other.
If on the browns I would then start unplugging them where they feed the
ignition switch, fusebox, main lighting switch, starter relay (where
provided) and ignition relay (where provided).
If still there then either some after-market wiring or component is
connected to a brown somewhere, or the wiring itself is shorting out,
although this usually gives a rather more catastrophic drain.
Incidentally when I took the battery back they had a gizmo that measured the
voltage, applied a known load for a known length of time then measured the
voltage again. From that it displayed the capacity, which was down to
172CCA from 250.
PaulH.
----- Original Message -----
From: "Hans Duinhoven" <h.duinhoven@planet.nl>
To: <mgs@autox.team.net>
Sent: Tuesday, December 16, 2003 8:15 PM
Subject: 16 miliamps drain
> It's the second time my GT had flat batteries.
>
> Where are 16 miliamps continuous current drain going to when the car is
> standing still and everything switched off.
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