short circuit?

We've had a problem on a 92 explorer. The battery wemt dead
and there was nothing left on. It happened after it was
left sitting for 5 days or so. I tested the battery terminals
(with the battery removed) didn't get an open circuit reading
even though nothing was turned on.

I assume there should be an open circuit, and this indicates that
we have something shorting?

Thanks.

On 19 Nov 2004 12:14:54 GMT, *selah* > wrote:

>We've had a problem on a 92 explorer. The battery wemt dead
>and there was nothing left on. It happened after it was
>left sitting for 5 days or so. I tested the battery terminals
>(with the battery removed) didn't get an open circuit reading
>even though nothing was turned on.
>
>I assume there should be an open circuit, and this indicates that
>we have something shorting?
>
>Thanks.

It could indicate a dead battery. :-)
What did you test the battery cables with? I assume a voltmeter?
A better test would be to use an ammeter; this will tell you if
there's a current draw.

--
Bill Funk
Change "g" to "a"

Sorry, I should have said that I tested the battery cables, with the
battery removed, and didn't get an open circuit.

In article >, Big Bill wrote:
> On 19 Nov 2004 12:14:54 GMT, *selah* > wrote:
>
>>We've had a problem on a 92 explorer. The battery wemt dead
>>and there was nothing left on. It happened after it was
>>left sitting for 5 days or so. I tested the battery terminals
>>(with the battery removed) didn't get an open circuit reading
>>even though nothing was turned on.
>>
>>I assume there should be an open circuit, and this indicates that
>>we have something shorting?
>>
>>Thanks.
>
> It could indicate a dead battery. :-)
> What did you test the battery cables with? I assume a voltmeter?
> A better test would be to use an ammeter; this will tell you if
> there's a current draw.
>

I assume you are referring to actually testing the vehicle wiring via
the battery cables, not the battery.
When you test the resistance (ohms), not the voltage, you shouldn't have an
open circuit as you are supplying a voltage to the circuit to test the
resistance. Since there is an onboard computer, clock, etc. all requiring a
voltage to operate, they will take whatever power is supplied, even though
it is inadequate to actually operate. Since this is the case, you cannot
read your vehicle as having an open circuit.

"*selah*" > wrote in message
...
| We've had a problem on a 92 explorer. The battery wemt dead
| and there was nothing left on. It happened after it was
| left sitting for 5 days or so. I tested the battery terminals
| (with the battery removed) didn't get an open circuit reading
| even though nothing was turned on.
|
| I assume there should be an open circuit, and this indicates that
| we have something shorting?
|
| Thanks.

Ok - thanks.

Is there some way to determine if there is a short somewhere? Is there a
listing of what the resistance should be?


"John Riggs" > wrote in message
...
> I assume you are referring to actually testing the vehicle wiring via
> the battery cables, not the battery.
> When you test the resistance (ohms), not the voltage, you shouldn't have
an
> open circuit as you are supplying a voltage to the circuit to test the
> resistance. Since there is an onboard computer, clock, etc. all requiring
a
> voltage to operate, they will take whatever power is supplied, even though
> it is inadequate to actually operate. Since this is the case, you cannot
> read your vehicle as having an open circuit.
>
> "*selah*" > wrote in message
> ...
> | We've had a problem on a 92 explorer. The battery wemt dead
> | and there was nothing left on. It happened after it was
> | left sitting for 5 days or so. I tested the battery terminals
> | (with the battery removed) didn't get an open circuit reading
> | even though nothing was turned on.
> |
> | I assume there should be an open circuit, and this indicates that
> | we have something shorting?
> |
> | Thanks.
>
>

The ohm-meter is notoriously inaccurate for most electrical systems tests.
It has it's uses when testing controlled continuity but in most instances,
voltage drop testing is better. There is no factory spec on "system
resistance"... if there was, it would be somewhere between 5 ohms and
infinity (just joking...).

For your situation, the logical procedure would be to charge the battery and
have it tested. If the battery passes, have the charging system tested.
After that, I can only suggest that you purchase the manual for your vehicle
and use the proper method for testing for parasitic draw. 50 milliamps
(after all the modules have "gone to sleep") is the factory spec on
parasitic draw.

Additionally, I would suggest referring to the manual that came with your
meter for the various ways that it can be used. Tread carefully in your
electrical testing... often, the unwary can create damage where none was
before. Recent vehicles make extensive use of "voltage divider" circuits
which makes these sorts of acidents less likely but we should always
excersize caution to avoid costly mistakes.




"*selah*" > wrote in message
...
> Ok - thanks.
>
> Is there some way to determine if there is a short somewhere? Is there a
> listing of what the resistance should be?
>
>
> "John Riggs" > wrote in message
> ...
>> I assume you are referring to actually testing the vehicle wiring via
>> the battery cables, not the battery.
>> When you test the resistance (ohms), not the voltage, you shouldn't have
> an
>> open circuit as you are supplying a voltage to the circuit to test the
>> resistance. Since there is an onboard computer, clock, etc. all requiring
> a
>> voltage to operate, they will take whatever power is supplied, even
>> though
>> it is inadequate to actually operate. Since this is the case, you cannot
>> read your vehicle as having an open circuit.
>>
>> "*selah*" > wrote in message
>> ...
>> | We've had a problem on a 92 explorer. The battery wemt dead
>> | and there was nothing left on. It happened after it was
>> | left sitting for 5 days or so. I tested the battery terminals
>> | (with the battery removed) didn't get an open circuit reading
>> | even though nothing was turned on.
>> |
>> | I assume there should be an open circuit, and this indicates that
>> | we have something shorting?
>> |
>> | Thanks.
>>
>>
>
>

On Sat, 20 Nov 2004 00:38:04 -0500, "*selah*" >
wrote:

>Ok - thanks.
>
>Is there some way to determine if there is a short somewhere? Is there a
>listing of what the resistance should be?

I posted this earlier, but maybe it didn't get through (I haven't seen
it)...
Use an ammeter with the battery connected. This will tell you what the
actual current draw is; there will always be some. Pulling fuses will
tell you what circuits are pulling how much. If the battery is
draining that quickly, you'll have a fairly large draw somewhere (or
the battery is going bad).

>
>
>"John Riggs" > wrote in message
...
>> I assume you are referring to actually testing the vehicle wiring via
>> the battery cables, not the battery.
>> When you test the resistance (ohms), not the voltage, you shouldn't have
>an
>> open circuit as you are supplying a voltage to the circuit to test the
>> resistance. Since there is an onboard computer, clock, etc. all requiring
>a
>> voltage to operate, they will take whatever power is supplied, even though
>> it is inadequate to actually operate. Since this is the case, you cannot
>> read your vehicle as having an open circuit.
>>
>> "*selah*" > wrote in message
>> ...
>> | We've had a problem on a 92 explorer. The battery wemt dead
>> | and there was nothing left on. It happened after it was
>> | left sitting for 5 days or so. I tested the battery terminals
>> | (with the battery removed) didn't get an open circuit reading
>> | even though nothing was turned on.
>> |
>> | I assume there should be an open circuit, and this indicates that
>> | we have something shorting?
>> |
>> | Thanks.
>>
>>
>

--
Bill Funk
Change "g" to "a"

Thanks to everyone for the input.

Was wondering what the current draw should be?

"Big Bill" > wrote in message
news
> On Sat, 20 Nov 2004 00:38:04 -0500, "*selah*" >
> wrote:
>
> >Ok - thanks.
> >
> >Is there some way to determine if there is a short somewhere? Is there a
> >listing of what the resistance should be?
>
> I posted this earlier, but maybe it didn't get through (I haven't seen
> it)...
> Use an ammeter with the battery connected. This will tell you what the
> actual current draw is; there will always be some. Pulling fuses will
> tell you what circuits are pulling how much. If the battery is
> draining that quickly, you'll have a fairly large draw somewhere (or
> the battery is going bad).
>
> >
> >
> >"John Riggs" > wrote in message
> ...
> >> I assume you are referring to actually testing the vehicle wiring
via
> >> the battery cables, not the battery.
> >> When you test the resistance (ohms), not the voltage, you shouldn't
have
> >an
> >> open circuit as you are supplying a voltage to the circuit to test the
> >> resistance. Since there is an onboard computer, clock, etc. all
requiring
> >a
> >> voltage to operate, they will take whatever power is supplied, even
though
> >> it is inadequate to actually operate. Since this is the case, you
cannot
> >> read your vehicle as having an open circuit.
> >>
> >> "*selah*" > wrote in message
> >> ...
> >> | We've had a problem on a 92 explorer. The battery wemt dead
> >> | and there was nothing left on. It happened after it was
> >> | left sitting for 5 days or so. I tested the battery terminals
> >> | (with the battery removed) didn't get an open circuit reading
> >> | even though nothing was turned on.
> >> |
> >> | I assume there should be an open circuit, and this indicates that
> >> | we have something shorting?
> >> |
> >> | Thanks.
> >>
> >>
> >
>
> --
> Bill Funk
> Change "g" to "a"

On Sun, 21 Nov 2004 02:41:55 -0500, "*selah*" >
wrote:

>Thanks to everyone for the input.
>
>Was wondering what the current draw should be?

Not positive (it will vary from vehicle to vehicle) but it should be
in the low milliamp range.

--
Bill Funk
Change "g" to "a"

50 ma.... that's .050 amps - after all the modules have gone to sleep.


"Big Bill" > wrote in message
...
> On Sun, 21 Nov 2004 02:41:55 -0500, "*selah*" >
> wrote:
>
>>Thanks to everyone for the input.
>>
>>Was wondering what the current draw should be?
>
> Not positive (it will vary from vehicle to vehicle) but it should be
> in the low milliamp range.
>
> --
> Bill Funk
> Change "g" to "a"