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Discussion Starter #1
So my wife's 99 grand Cherokee will drain the battery if it doesn't run for about a day
I put my current probe on both power cables and only one of them has a draw of about .7 amps with all doors and hood light off
I pulled each fuse individually and these are the results

Internal fuse 28 draws about .2 amps
Internal fuse 29 draws about .1 amps
Internal fuse 17 draws about .05 amps


Internal fuse 8 draws about 1.5 amps but I belive this is from having the door open to pull the fuse because all the lights go out when I pull it

How much current draw should the battery see when the door is closed and all the lights are out?

Does anyone have a fuse diagram so I can see what's on those circuits?

Thanks all
 

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You should see less than .050 amps when all modules are asleep. That car is older but prob still needs some time to go to sleep. Take a screwdriver and latch the door latch so lights go off.
 

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Have you looked into the condition of the battery? It may not be holding the charge. I don't think .7 would be enough to drain a battery in a day. I could be wrong.

I'm not going to venture on what the normal amp draw is, hopefully someone else can provide that.
 

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May not be related, but something to check. My 99 Dodge Ram would do the same thing (although it would take longer, but I have 2 batteries). Does your Jeep have "electric" seatbelts? Meaning, if you disconnect the battery, will the seatbelt still pull out of the retracter?

My Dodge has the seatbelts built into the seat. There is a module under the seat. If you disconnect the module, the drain will go away, but you can't use the seatbelt.

When I want to use the seatbelt, I plug it in, then unplug it when I won't be driving the truck for awhile.

Something to check.
 

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Discussion Starter #5
So I just double checked and with everything closed and fuses 28 and 29 pulled there is almost no draw. With them plugged in it's like .3 amps.

The underhood light draws about .7 amps so the draw is half a light and we know how fast leaving an interior light on can kill a battery. Guess I need to dig deeper into those 2 circuits.
 

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Check the continuity between the alternator case and power post. I've had a dodge drain the battery due to the alternator going bad.
 

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Alternators frequently cause it... maybe it's not sitting in the same position when your testing it. I would load test the battery. .7 shouldn't drain it.
 

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Check the continuity between the alternator case and power post. I've had a dodge drain the battery due to the alternator going bad.
Alternators frequently cause it... maybe it's not sitting in the same position when your testing it. I would load test the battery. .7 shouldn't drain it.
I would damn sure be looking at this. Put your ammeter between the alternator output stud and the charge wire.

You have a separate stereo amp? On many radios / amps the output circuit is "battery hot" at all times.

Any fuses you've missed? Time to start on various modules including the ECU
 

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50mA at the most.
 

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May not be related, but something to check. My 99 Dodge Ram would do the same thing (although it would take longer, but I have 2 batteries). Does your Jeep have "electric" seatbelts? Meaning, if you disconnect the battery, will the seatbelt still pull out of the retracter?

My Dodge has the seatbelts built into the seat. There is a module under the seat. If you disconnect the module, the drain will go away, but you can't use the seatbelt.

When I want to use the seatbelt, I plug it in, then unplug it when I won't be driving the truck for awhile.

Something to check.
ONLY the DODGE rams with 4 doors of that era used a seat belt timer module. Due to the way the rear doors opened back instead of forward, the seat belts are completely mounted inside the seat. So they had to use an electronic locking mechanism since the seat wouldn't neccesarily be in the optimum position all the time for the seat belt to properly lock. The factory spec was less than 350 milliamps after the vehicle has sat for 30 minutes idle for the BCM and such to go to sleep. I would also be looking very closely at the alternator for excessive current draw.
 

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Well that's not a "stuck relay." And if the coil is energized, the relay is probably going to be holding on the switched load.
 

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Have you looked into the condition of the battery? It may not be holding the charge. I don't think .7 would be enough to drain a battery in a day. I could be wrong.

I'm not going to venture on what the normal amp draw is, hopefully someone else can provide that.
I had that on one of my cars a couple of years ago. After messing with it on and off for a couple of weeks I disconnected the battery cable. It still went dead in a couple of days. New battery and no problem since.
 

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My brothers 99 will kill the battery after it sits a couple days, we fixed it once but it came back again, it's been the starter in his case. Replaced it once and it stopped killing the battery, it stated doing the same thing again a year or so ago, figure it's the starter again. It's a bitch to change and he drives it every day now vs. Once a week so it's been a non issue anymore.
 

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Check the mirror on the backside of the passenger sun visor. If it has the little lights on it, disconnect them. Those are known on many vehicles to cause dead batteries when the switch stops working.
 
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