Really bad draw

[Axel-ander92]

Hi guys.

Really freaking stressed right now. My 06 limited is not running due to a really bad draw of .221 a. We can literally watch the voltage across the terminals drop like a stone when we shut it off. Alternator had been tested and its working fine. Battery was tested before the draw test and replaced so its brand new not even a week old. We've pulled every single fuse inside and out and it doesn't change the draw at all. We unplugged the head unit and its still draining. We unplugged the "brain" and it still drains. We have no idea what to check next except maybe an ignition switch? Really need this thing running as its my daily and I have to keep having coworkers pick me up. Can anyone help before I just push it off a cliff and jump after it?

Thanks in advance

 

[kage860]

You can disconnect the battery when not using the jeep to keep it from draining to solve your getting to work issue for the time being.

 

[Axel-ander92]

I suppose but id much rather get it fixed asap. I've read renegade04 has had issues similar to this but not sure if it was the exact same. I'm sure pulling a certain fuse would have killed the drain if it was an ignition switch. Auto-electrical is definitely not my strong suit but my car audio buddy says .221 is a pretty big draw. So much so that it can drain my battery to dead in about 3 hours. Its horrible and I need to fix it I just hope its cheap as I have a wife and child to take care of and I'm the only income by choice I may add. So no cracks about my better half! Lol

 

[LibertyTC]

Charge the battery -don't let it drain flat, it will kill the battery.
Connect a volt meter and start pulling fuses one by one, while monitoring the voltage.
Check the under hood fuse panel as well as the one inside drivers compartment by kick panel left of steering wheel.
If the voltage does not drop/stabilizes, you found the circuit.
Check the under hood fuse panel as well as the one inside drivers compartment by kick panel left of steering wheel.

Also: In the under hood power distribution center (fuse panel) there is a storage fuse #15 labelled IOD(ignition off draw)that can be removed, to kill all power.
Refer to your owners manual to confirm fuse #15

 

[Axel-ander92]

Charge the battery -don't let it drain flat, it will kill the battery.
Connect a volt meter and start pulling fuses one by one, while monitoring the voltage.
Check the under hood fuse panel as well as the one inside drivers compartment by kick panel left of steering wheel.
If the voltage does not drop/stabilizes, you found the circuit.
Check the under hood fuse panel as well as the one inside drivers compartment by kick panel left of steering wheel.

Also: In the under hood power distribution center (fuse panel) there is a storage fuse #15 labelled IOD(ignition off draw)that can be removed, to kill all power.
Refer to your owners manual to confirm fuse #15

If we pulled all the fuses under the dash drivers side and under the hood wouldn't that have dropped the .221 to under .01 around where it it should be though? Not trying to be a smartass I'm being serious. Cuz I mean ever fuse was pulled and there was no drop anywhere. Sooooooo stumped..

 

[Billwill]

If you have pulled every fuse, inside the cabin and under the hood and still have a problem then try disconnecting the thick wire going to the alternator...make sure that you have disconnected the battery before removing this cable(fusable link).

If this cable is causing the current drain then it means that some diodes inside the alternator may have shorted out.

What year/model is your KJ so I can look into the correct wiring diagrams.

 

[Axel-ander92]

Also is it possible that the multimeter would show a draw if the battery was just not holding a charge? We can watch the voltage of the battery drop by the .0x its crazy... I'm really stumped

 

[towpro]

something don't sound right here. if you have .25a draw, W=Current x voltage
current is .25a, x 12 volt so W so that is 3 watts draw

Guessing your battery is good for 75Ah (amp hours)

Now I stole this formula from internet
10X battery capacity in amp hours divided by load = run time in hours.

so we have 10x 75= 750, divided by 3 = 250 hours, but you never want to run a batter below 50% so that is 125 hours.

your battery should be able to carry that 3w load for 125 hours (almost 5 days) before its 1/2 way discharged.

 

[Axel-ander92]

something don't sound right here. if you have .25a draw, W=Current x voltage
current is .25a, x 12 volt so W so that is 3 watts draw

Guessing your battery is good for 75Ah (amp hours)

Now I stole this formula from internet
10X battery capacity in amp hours divided by load = run time in hours.

so we have 10x 75= 750, divided by 3 = 250 hours, but you never want to run a batter below 50% so that is 125 hours.

your battery should be able to carry that 3w load for 125 hours (almost 5 days) before its 1/2 way discharged.

One would think. But! My old man just pointed something out. I replaced the battery last Tuesday. The alternator tests fine, that is, it charges the system. But! It could have a bad diode so as soon as I shut off the car it starts to drain. And seeing as how we never fully charged the battery when pulling fuses it could drain pretty fast. My only concern is this: we unplugged the little plug from the back of the alternator towards the firewall but we didn't disconnect the charge wire I assume it could be called? The cable with the nut. So is it possible that even though we unplugged the plug from the back that it could still have drawn power through the charge cable?

 

[Axel-ander92]

If you have pulled every fuse, inside the cabin and under the hood and still have a problem then try disconnecting the thick wire going to the alternator...make sure that you have disconnected the battery before removing this cable(fusable link).

If this cable is causing the current drain then it means that some diodes inside the alternator may have shorted out.

What year/model is your KJ so I can look into the correct wiring diagrams.

Wow I didn't even see your comment yeah I'm replacing the alternator tonight seeing as how the gal I bought it from was running a 15 inch jl audio sub with no cap or secondary power source at all. I'm almost certain its a diode issue now

 

[Axel-ander92]

The problem was indeed the alternator. Its banging like a champ again!

 

[Billwill]

The problem was indeed the alternator. Its banging like a champ again!

Great!

And you were correct that 0.250 A was a major current draw.

This is 250 mA (milli amps) while you would expect to get about a max draw of 30 mA which is what the Jeep would draw due to the clock running, the BCM idling away and the alarm system in action.

In answer to your other question as to if a battery disconnected completely could discharge the answer is yes.

All batteries have a built in resistance in series with the battery and a built in parallel resistance so even a new battery standing on a shelf will discharge due to the parallel resistance.

A nice new battery has low resistances so could last for months on the shelf with no problems while a very bad old battery could have high parallel resistance so it will discharge rather rapidly.

 

[boboborino]

I suppose but id much rather get it fixed asap. ....................need to fix it I just hope its cheap as I have a wife and child to take care of and I'm the only income by choice I may add. So no cracks about my better half! Lol

Wouldn't even think of it! We've (my wife and I)been there done that. Believe me your kid(s) will be waaaaaaaay better off in the long run! I can definitely relate to how stress-full it is when your only vehicle breaks down. I am glad you got it worked out. Enjoy Life and your family.

Bert

 

[JasonJ]

...

In answer to your other question as to if a battery disconnected completely could discharge the answer is yes.

All batteries have a built in resistance in series with the battery and a built in parallel resistance so even a new battery standing on a shelf will discharge due to the parallel resistance.

A nice new battery has low resistances so could last for months on the shelf with no problems while a very bad old battery could have high parallel resistance so it will discharge rather rapidly.

Absolutely correct. I was taught back in ASE diag specialist training that a new battery can expect to lose 0.10v per month. Which is why if you were to check new batteries on the shelf at a parts store, you'll see voltages all over the place.

When they get to be about a year old, most are about 11.5v, which is when we discounted them and sold them cheap when I worked retail parts; but more importantly why it's important to look at date of manufacture and to actually check the voltage and top it off on a trickle charger (always if possible) before putting into service.

 

[Axel-ander92]

Absolutely correct. I was taught back in ASE diag specialist training that a new battery can expect to lose 0.10v per month. Which is why if you were to check new batteries on the shelf at a parts store, you'll see voltages all over the place.

When they get to be about a year old, most are about 11.5v, which is when we discounted them and sold them cheap when I worked retail parts; but more importantly why it's important to look at date of manufacture and to actually check the voltage and top it off on a trickle charger (always if possible) before putting into service.

Yeah like I previously said I replaced the battery last Tuesday and got the alternator in last night and today my new battery kicked the bucket because it was drained to absolutely nothing like 4 times in the last week. Cca is 800 and it was putting out like 227 at 11.9. So new battery under warranty in and hopefully this is the end of my dreaded electric problems and on to bigger and better things like bigger tires, more lift, regearing and cosmetics lol I'm personally looking forward to what I'm gonna do with the hood in the spring. Should look pretty awesome!

 

[Axel-ander92]

Ok so alternator has been replaced twice along with battery. No shorts in the charging cable. And chance a bad starter is draining it over night? If I jump it it starts fine so I know its power related. But I can't believe that it could be a bad alternator again especially if the vehicle stays running fine after its started. Also if I drive it for a while and park it it'll still start fine for about 3 hours. If I don't start it for three hours its dead. Really pissed