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shellback91

Battery "Draining" Question

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I've noticed that my rig  is a little slow to turn over lately.  I've seen no engine codes so I took it down to AutoZone to have the battery checked.(I replaced the battery about 6-8 months ago)  They said the battery is fine, just needs charged.  The message they showed me on the tester was "Light left on, key turned off drain". (Something like that)  I am not sure what to make of this and cannot find anything relevant on the interwebs.  My light bar has been removed and that wiring has been tucked away an d my 2 pod lights are never on.

 

Any thoughts on this?

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7 minutes ago, Trail Toy said:

Do you have a light under the hood?  Glove box light?  Dome light?  Some other accessory light?  Those come to mind, good luck getting it figured out Marty! 

I have none of the above. I am pretty good about making sure doors are closed etc.. I've got a long drive later this week, that should charge it up enough.

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Grab the ole clamp on amp meter, hook it to the positive cable as close to the battery as possible (there should be a tiny draw with the key off). Then, one at a time, start pulling fuses/relays, if something is "on" you'll see a change in the meter reading (drop) when you pull the offending circuit. This is a easy way to troubleshoot the mysterious force called electricity 😉funny_picdump_640_high_34(1).jpg.f5177ba68ee7de212d8bda981dca3441.jpg

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Wanted to mention we had a battery from Costco go bad in 3 months! Costco guy said they have a bunch being returned recently within just a few months of purchase.  Good luck!

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9 hours ago, shellback91 said:

I've noticed that my rig  is a little slow to turn over lately.  I've seen no engine codes so I took it down to AutoZone to have the battery checked.(I replaced the battery about 6-8 months ago)  They said the battery is fine, just needs charged.  The message they showed me on the tester was "Light left on, key turned off drain". (Something like that)  I am not sure what to make of this and cannot find anything relevant on the interwebs.  My light bar has been removed and that wiring has been tucked away an d my 2 pod lights are never on.

 

Any thoughts on this?

 

was this message on some sort of battery/charging-system tester they hooked to the battery while it was in-vehicle, or was the tester something they hooked to the OBD2 port (inside the vehicle, below the steering wheel)?

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on a JK the acceptable IOD (ignition-off draw) is 5 to 35 mA (i.e. 0.005 to 0.035 Amps). when testing, you need to remove the key, be sure all the doors are closed, all lights are off, etc. then you still have to wait 3 minutes from the time you connect the multimeter for all the various electronic systems to go to sleep to get the true IOD reading.

 

Autozone probably used a battery/charging-system tester and either didn't use it correctly at all, or at least didn't wait the 3 minutes. either way, the generic error without an actual mA reading is pretty useless. do the IOD test as @Stacey and Scott mentioned (and outlined in detail below) and see what you come up with. if your IOD is around 35 mA or less, then your rig is fine and you probably have a junk battery that will just get weak again soon. please let us know what you find!

 

 

IGNITION-OFF DRAW TEST

 

The term Ignition-Off Draw (IOD) identifies a normal condition where power is being drained from the battery with the ignition switch in the Off position. A normal vehicle electrical system will draw from five to thirty-five milliamperes (0.005 to 0.035 ampere) with the ignition switch in the Off position, and all non-ignition controlled circuits in proper working order. Up to thirty-five milliamperes are needed to enable the memory functions for the Powertrain Control Module (PCM), digital clock, electronically tuned radio, and other modules which may vary with the vehicle equipment.

A vehicle that has not been operated for approximately twenty days, may discharge the battery to an inadequate level. When a vehicle will not be used for twenty days or more (stored), remove the IOD fuse from the Totally Integrated Power Module (TIPM). This will reduce battery discharging.

Excessive IOD can be caused by:

Electrical items left on.
Faulty or improperly adjusted switches.
Faulty or shorted electronic modules and components.
An internally shorted generator.
Intermittent shorts in the wiring.

 

If the IOD is over thirty-five milliamperes, the problem must be found and corrected before replacing a battery. In most cases, the battery can be charged and returned to service after the excessive IOD condition has been corrected.

1. Verify that all electrical accessories are off. Turn off all lamps, remove the ignition key, and close all doors. If the vehicle is equipped with an illuminated entry system or an electronically tuned radio, allow the electronic timer function of these systems to automatically shut off (time out). This may take up to three minutes.

 

2. Determine that the under-hood lamp is operating properly, then disconnect the lamp wire harness connector or remove the lamp bulb.

 

3. Disconnect the battery negative cable.

 

4. Set an electronic digital multimeter to its highest amperage scale. Connect the multimeter between the disconnected battery negative cable terminal clamp and the battery negative terminal post. Make sure that the doors remain closed so that the illuminated entry system is not activated. The multimeter amperage reading may remain high for up to three minutes, or may not give any reading at all while set in the highest amperage scale, depending upon the electrical equipment in the vehicle. The multimeter leads must be securely clamped to the battery negative cable terminal clamp and the battery negative terminal post. If continuity between the battery negative terminal post and the negative cable terminal clamp is lost during any part of the IOD test, the electronic timer function will be activated and all of the tests will have to be repeated.

 

5. After about three minutes, the high-amperage IOD reading on the multimeter should become very low or nonexistent, depending upon the electrical equipment in the vehicle. If the amperage reading remains high, remove and replace each fuse or circuit breaker in the Totally Integrated Power Module (TIPM), one at a time until the amperage reading becomes very low, or nonexistent. Refer to the appropriate wiring information for complete TIPM fuse, circuit breaker, and circuit identification. This will isolate each circuit and identify the circuit that is the source of the high-amperage IOD. If the amperage reading remains high after removing and replacing each fuse and circuit breaker, disconnect the wire harness from the generator. If the amperage reading now becomes very low or nonexistent, there may be an internal short in the generator. After the high-amperage IOD has been corrected, switch the multi-meter to progressively lower amperage scales and, if necessary, repeat the fuse and circuit breaker remove-and-replace process to identify and correct all sources of excessive IOD. It is now safe to select the lowest milliamp scale of the multimeter to check the low-amperage IOD.


CAUTION: Do not open any doors, or turn on any electrical accessories with the lowest milliamp scale selected, or the multimeter may be damaged.


6. Observe the multimeter reading. The low-amperage IOD should not exceed thirty-five milliamp (0.035 ampere). If the current draw exceeds thirty-five milliamp, isolate each circuit using the fuse and circuit breaker remove-and-replace process in STEP 5. The multimeter reading will drop to within the acceptable limit when the source of the excessive current draw is disconnected. Repair this circuit as required; whether a wiring short, incorrect switch adjustment, or a component failure is at fault.

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2 hours ago, theksmith said:

 

was this message on some sort of battery/charging-system tester they hooked to the battery while it was in-vehicle, or was the tester something they hooked to the OBD2 port (inside the vehicle, below the steering wheel)?

It was a tester they connected to the battery while the battery was still in-vehicle.  I may take another run at AutoZone today or tomorrow with the weekday crew being there. It's covered for 3 years so I have to replace it I should be covered. I should probably pick up meter too as @Stacey and Scott mentioned.

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20 minutes ago, shellback91 said:

It was a tester they connected to the battery while the battery was still in-vehicle.  I may take another run at AutoZone today or tomorrow with the weekday crew being there. It's covered for 3 years so I have to replace it I should be covered. I should probably pick up meter too as @Stacey and Scott mentioned.

 

this Amazon brand one is a excellent value multimeter.

 

or locally, this Commercial Electric one is in-stock at most Home Depot stores.

 

those are both under $50 with auto-ranging, backlight, and 10 Amp DC current capability. like with anything else, you can easily spend more than that, but those should be perfectly sufficient for basic automotive troubleshooting. 

Edited by theksmith
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Is it possible your alternator is beginning to fail to charge the batts?

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2 hours ago, 4x4tographer said:

Is it possible your alternator is beginning to fail to charge the batts?

That crossed my mind too. The battery I replaced last year was old and needed to go, this one is newish. According to the dude at AutoZone my alternator is fine.  That said, I am going back down there today, retest and maybe force their hand to replace the battery.  I may even schedule an appointment with the dealership for the alternator depending on what happens today. I am still under warranty so if it's bad then I should be covered.

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