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Unread 12-05-2012, 09:26 PM   #1
imjohnm
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Mechanics Stumped - Unfused battery drain

140 ma drain even with all fuses out & hot alternator lead unhooked. No alarm, amp or bootleg wires visible. Any ideas? 96 4.0 4wd Laredo

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Unread 12-05-2012, 10:05 PM   #2
phitmein
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have you had your battery load tested yet ?
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Unread 12-05-2012, 10:54 PM   #3
imjohnm
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Yep, tests good.
Thanks.
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Unread 12-06-2012, 12:16 AM   #4
jnicewan
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Did you pull the relays and circuit breakers too? The draw has to be coming from somewhere, you have not disconnected everything if you are seeing a 140mA draw. Never seen one but I guess its possible that the starter motor has a draw since its directly wired to the battery. I would be happy to see the draw fall below 50mA but usually less than half that is the norm.
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Unread 12-06-2012, 12:47 AM   #5
KoreaZJ
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Pulling PDC fuses isolates most everything. You disconnected the alternator, so that leaves only PDC housing and starter still connected? Disconnect battery feed cable from PDC to separate it from starter.
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Unread 12-06-2012, 02:12 AM   #6
phitmein
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If a parts store did the test I wouldn't trust what they said because I have seen them be wrong more than once.

I have a load tester and do it myself.

The last battery I had that was driving me nuts I didn't have my load tester handy so I charged my battery all the way and took off the positive cable for three days then put it back on and it was too weak to turn it over.

Dead cell I think.

If it is not your DD you might want to try that.

Phit
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Unread 12-06-2012, 06:54 AM   #7
chucktownzj
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When they tested your battery did they load test it. A lot of times parts stores hook them up to computerized testers that do not catch a bad cell. Sometimes the best test is a load tester. 10sec full load, should not drop much below 10v.
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Unread 12-06-2012, 09:04 AM   #8
imjohnm
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Sears did a 10 second load test and I pulled every PDC use and relay one by one plus the alternator red lead, but the drain just hangs in there. I've been working with the ground side off the battery and removing it when I leave the car for a few hours. This really impresses a hot date and the super wealthy. Next I'll try disconnecting the lead to the starter solenoid, but I'm wondering if I should be working from the hot side of the battery.

Thanks guys for all the help. Logic and persistence will prevail.
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Unread 12-06-2012, 09:13 AM   #9
cliffordmck72
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It doesn't matter what side you hook it up on, as long as the meter is in series. Battery disconnected, Cable to meter lead and battery to other meter lead.
If you're lost I suggest starting with the larger feeds as suggested above, once you find the big one work your way trough that circuit using the wiring diagram.
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Unread 12-06-2012, 09:26 AM   #10
chucktownzj
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Do you have a digital voltmeter? Take the negitive terminal off the battery. Connect the red wire on the meter to your neg. battery contection. Connect the black wire to the neg. post on the battery. Set your meter to 10A. Make sure the red meter wire is pluged into the 10A slot on the meter and the black lead in the neg.. This should complete your circuit and give you draw amps. Make sure the doors are closed(interior lamps off) and nothing in the cig lighter. Do not turn anything on(will blow meters internal fuse). At this put you can start undoing stuff. Undo your starter and see if the draw goes away. Unhook you fuse box from main connection. If all is unplugged and still showing a draw then your doing something wrong.
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Unread 12-06-2012, 11:56 AM   #11
imjohnm
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I have an analog meter that shows a consistent draw even with the PDC lead off. Next the starter.
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Unread 12-06-2012, 12:18 PM   #12
chucktownzj
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Quote:
Originally Posted by imjohnm View Post
I have an analog meter that shows a consistent draw even with the PDC lead off. Next the starter.
I would see if you can get (borrow) a digital meter to double check yourself. Analog meters create there own voltage (not for amp testing) to test and are not the best to use in an automotive environment.
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Unread 12-06-2012, 02:33 PM   #13
cmax72ms
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Go to a marine store and get a battery disconnect switch. Mine works great
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Unread 12-06-2012, 05:49 PM   #14
phitmein
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cmax you beat me to it and you can get them from RV supply places too I think.
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Unread 12-06-2012, 08:37 PM   #15
imjohnm
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Aha - borrowed a digital multimeter and going through the fuses again found that pulling the 50 amp fuse stops the drain. Have to get a diagram to see what is on that circuit. The 180 ma drain is there even with the alternator and solenoid wires removed, but stops when the PDC wires removed or the 50 amp fuse.
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