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> Parasitic Battery Drain source found: Now what?
moneysmarts
post Apr 6 2011, 03:50 PM
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Long-time- no-post!
Hi all.
Just took the car out of storage from winter, looking forward to driving.
My new battery keeps draining overnight.
So I tapped in-line my multimeter and started pulling fuses and relays to locate the source.
When I pulled the alternator wiring harness plug from the relay board, the volts/amps dropped to zero. Bingo!
But now what do I do? (IMG:style_emoticons/default/confused24.gif) Do I have a bad alternator or can I diagnose further?
Thanks for the help.
I'd hate to have to struggle to replace that bad boy for nothing.
Steve
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r_towle
post Apr 6 2011, 03:53 PM
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how far are you from Tyngsboro?
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messix
post Apr 6 2011, 03:54 PM
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diode in the alt is blown and is energizing the field from the battery. get a new alt.
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Root_Werks
post Apr 6 2011, 03:54 PM
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Plug the alt harnes back in and the take the volt reg out. Might just be a bad volt reg?

Those are cheap.
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moneysmarts
post Apr 6 2011, 03:54 PM
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QUOTE(r_towle @ Apr 6 2011, 01:53 PM) *

how far are you from Tyngsboro?


I'm in Leominster.
25 min.s
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r_towle
post Apr 6 2011, 03:55 PM
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unplug just the alternator at the alternator.
It may be the reverse light switch....same part of the harness and it may be the same plug.

Rich
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moneysmarts
post Apr 6 2011, 03:59 PM
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QUOTE(r_towle @ Apr 6 2011, 01:55 PM) *

unplug just the alternator at the alternator.
It may be the reverse light switch....same part of the harness and it may be the same plug.

Rich



Ok I'll pull the voltage regulater first.
Then I'll try unpluging the alt. Can I access it by hand from under the car?
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r_towle
post Apr 6 2011, 04:01 PM
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not easily...but yes you can.

Chelmsford Auto Electric is where to bring it if it needs rebuilding.
Up near the tyngsboro bridge...

Rich
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moneysmarts
post Apr 6 2011, 04:07 PM
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I just pulled out the voltage regulator from the relay board and my meter still shows a power drain. (IMG:style_emoticons/default/mad.gif)

So now I'll try disconnecting the alternator directly.
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moneysmarts
post Apr 6 2011, 04:09 PM
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[quote name='r_towle' date='Apr 6 2011, 02:01 PM' post='1454691']
not easily...but yes you can.

How else can I do it?
Snip the wires in the engine compartment, then splice them back together when I finish checking?

Steve
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r_towle
post Apr 6 2011, 04:11 PM
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well, that might seem easier, but it wont be in the long run.
Jack her up and climb underneath....

Rich
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76-914
post Apr 6 2011, 05:22 PM
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QUOTE(r_towle @ Apr 6 2011, 03:11 PM) *

well, that might seem easier, but it wont be in the long run.
Jack her up and climb underneath....

Rich

(IMG:style_emoticons/default/laugh.gif) (IMG:style_emoticons/default/agree.gif) Spoken like an old pro. We can sit here and talk all day or we can climb under and do it in a few. The voice of experience is the wise teacher.
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SLITS
post Apr 6 2011, 05:24 PM
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The alt harness unplugs from the relay board ............ the hot wire to the alt is on the same terminal on the starter solenoid as the feed to the starter from the battery.
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moneysmarts
post Apr 6 2011, 05:35 PM
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QUOTE(SLITS @ Apr 6 2011, 03:24 PM) *

The alt harness unplugs from the relay board ............ the hot wire to the alt is on the same terminal on the starter solenoid as the feed to the starter from the battery.


Hi Ron;
Are you saying I can just loosten the nut on the starter solonioid and take that hot wire off?
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moneysmarts
post Apr 6 2011, 06:48 PM
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Rather than pulling apart the sheet metal to get at the alternator, I disconnected the red hot wire that was attached to the starter solonoid (and positive battery lead).
My multimeter dropped to zero. Is this now telling me that the alt. was the parasite?
And if so, should I have mine rebuilt or just source a new one?
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messix
post Apr 6 2011, 06:51 PM
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QUOTE(moneysmarts @ Apr 6 2011, 05:48 PM) *

Rather than pulling apart the sheet metal to get at the alternator, I disconnected the red hot wire that was attached to the starter solonoid (and positive battery lead).
My multimeter dropped to zero. Is this now telling me that the alt. was the parasite?
And if so, should I have mine rebuilt or just source a new one?

yes the diodes are blown and it needs to be rebuilt. [diodes are like a one way valve to electricity]
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moneysmarts
post Apr 6 2011, 07:05 PM
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yes the diodes are blown and it needs to be rebuilt. [diodes are like a one way valve to electricity]
[/quote]


Alrighty.
When I jump the car and have it running, my multimeter shows that the alternator is charging the battery, though. Would it still work that way if the diodes were shot?
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messix
post Apr 6 2011, 07:15 PM
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[quote name='moneysmarts' date='Apr 6 2011, 06:05 PM' post='1454764']
yes the diodes are blown and it needs to be rebuilt. [diodes are like a one way valve to electricity]
[/quote]


Alrighty.
When I jump the car and have it running, my multimeter shows that the alternator is charging the battery, though. Would it still work that way if the diodes were shot?
[/quote]
yah, for a while, it's going to over load the ones that are still working and blow all of them.

it won't be making the full rated output in current.

the diodes convert the a/c that the "alternator" makes into d/c, by taking voltage at 180 phases ...... well it gets complicated to explain in text and is easier to do on a chalk board.

look it up here http://en.wikipedia.org/wiki/Rectifier
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moneysmarts
post Apr 6 2011, 07:20 PM
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OK
Thanks much.
I'll have to pull it out tomorrow.
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Root_Werks
post Apr 6 2011, 08:59 PM
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Troy is my hero. (IMG:style_emoticons/default/pray.gif)
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