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Electrical parasite

Autozone tested my old battery, it was bad. Picked up a replacement and am going to start looking for the root of my problem.

Battery voltage when disconnected: 12.8v
Battery voltage when car is running with lights off: 14.0v
Battery voltage when car is running with lights (IceShark kit) on: 13.88v
Battery voltage when connected, car turned off: 12.8...7...6...5

Voltage drops .01v every 3 seconds. Seems like a pretty enormous parasite. I'm searching for common threads about this, basically want to document what I find here. For now the battery is disconnected. Should I also put it on the trickle-charger or will it be okay as it is?

Oh yeah, and the car sounded *so* awesome after not hearing her purr for a few months.

Any comments/suggestions appreciated
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1983 944 - Sable Brown Metallic / Saratoga / LSD : IceShark Light Kit
Old 01-22-2006, 06:15 PM
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Do the same test, but start pulling fuses one by one untill the draw stopps. This will at least tell you what circuit the draw is on.
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Old 01-22-2006, 06:30 PM
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.18A draw at the battery... I'm going through fuses now.

When I first connect the meter, my alarm clicks and it jumps to .3a, then settles at .18. I wonder how much the factory alarm pulls all by itself on a normal system?
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Old 01-22-2006, 06:47 PM
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Looks like I'm dealing with a heisenbug here... I checked a row of fuses and got nothing, then went back up the battery to make sure I haven't lost my mind and it now shows almost no draw. Bounces between .00 and .01A slowly.

Could re-seating my fuses have done anything?
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Old 01-22-2006, 07:05 PM
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I wouldn't think so but maybe. I would think it may have broke a set of contacts/relays loose and stopped the electrical drain. If you have a relay that is staying engaged and you completely stop the current, it may cool down and the contacts disengage and now it won't draw current again until you turn that accessory back on. I would restart the car and see if the current draw comes back after you shut it off again. Another thing to check may be the alternator...regulator may be stuck and it's drawing power back after you shut the car off. If the car is drawing current and then you disconnect the battery and reconnect it, does the current draw come back or does it do what you seen after you pulled the fuses? If you can get it to start drawing current again, keep the amp meter connected and disconnect the fuses one by one and check the meter after you pull each fuse to see when the current draw slows down. Then that's the circuit you want to look at. Let us know what you are finding.

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Old 01-22-2006, 07:43 PM
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Also, if the diode pack on the alt. are weak, it can do the same thing. But again, try and find the circuit the draw is on.
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Old 01-22-2006, 09:01 PM
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I didn't think 18 milliamps was enough to draw the battery down, let alone that quick.
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Old 01-23-2006, 04:57 AM
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That's not 18 milliamps, but 180 milliamps.
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Old 01-23-2006, 08:25 AM
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Oh, yeah.

That would be a problem.

A big problem.

I saw something similar when I had a stuck relay.

Did you try pulling the relays? I positioned my multimeter so that I could see it as I pulled fuses and relays. I would check the reading, pully one fuse, check the reading again, then replace the fuse. I did this all the way down the line until I found the window relay was sticking...
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Old 01-23-2006, 09:34 AM
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Quote:
Originally posted by legion
Did you try pulling the relays? I positioned my multimeter so that I could see it as I pulled fuses and relays. I would check the reading, pully one fuse, check the reading again, then replace the fuse. I did this all the way down the line until I found the window relay was sticking...
I haven't pulled any relays yet, but this evening when I get back to it I'll give it a shot. I need to pick up some alligator clamps so I can keep my meter connected whilst I pull fuses like you suggested. It was hard to tell sometimes if the probes were making a good enough connection on the fuse panel. This should be a lot easier. Thanks for the tip!

Razor: it's totally possible that my voltage regulator is bad... I took my old alternator to get tested at Autozone and the guy messed with the adjustable regulator that came with my IceShark kit. When I got my new alternator, I used the new regulator that came with it. I probably should put the adjustable one back in and figure out what it's supposed to be set at.
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Old 01-23-2006, 09:41 AM
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You are definitely doing the right things to find it. Good Work. Let us know what you find.
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Old 01-23-2006, 09:50 AM
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All fuses checked out fine... I found several where the PO or previous mechanic swapped higher amperage fuses, so I put in correct ones. Hopefully if the problem shows up again it'll just blow a fuse so I get a better indiciation.

I'm starting on relays now. I might need to find someone with tinier hands to help with these. There's just not much space in there. :/
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Old 01-28-2006, 12:59 PM
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Can anyone imagine why I would have two DME relays installed? one is in the correct #2 position, but the other is in the empty space at #5 (i might have to doubelcheck). I removed the second one and started the car up, it ran fine.

... Still haven't found the drain, but it feels like progress at least.
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Old 01-28-2006, 03:48 PM
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#5 is for the key buzzer. Looks like you may have found your extra DME relay. Does it have "DME" on the top?
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Old 01-28-2006, 04:42 PM
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hey guys i'm having a similar problem as bryanthompson...

87 944 S battery slowly drains after 4 - 5 days its dead. Replaced the battery and did a fuse-by-fuse amperage draw test.

The DME control unit is pulling 60 milliamps, the radio is pulling 60 milliamps and the clock is pulling 20 milliamps for a total of 140 milliamps....is that enough to drain the battery within a week and if so which one of those circuits is pulling too much current?
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Old 01-29-2006, 11:30 AM
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Which DME circuit did you test?
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Old 01-29-2006, 09:47 PM
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i tested all the circuits, but the one that was labeled "control unit DME (4 Vent.)" which was the 7th fuse in the box. When I tested the current after I pulled that fuse it was 60 milliamps less.
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Old 01-30-2006, 04:11 AM
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