Parasitic draw

[Cali-JeepJL]

When I leave my Jeep for 2-4 weeks sitting without starting it I’m finding the battery is dead. If I leave it on a battery tender it’s ok

I’m trying to locate the parasitic draw. I’ve disconnected the negative terminal from the battery and measured the draw with my multimeter and am seeing between 400-800ma of draw.

I read a post on this site to measure the draw by disconnecting the ground thats connected to the body next to the battery above the passenger wheel well (near the fuze box). When I measure it there I see 30ma draw.

whats the best way to do this? Why would the two different measure points show such different measures?

Has anyone else measured parasitic draw and if so how did you do it?

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[OldGuyNewJeep]

When I leave my Jeep for 2-4 weeks sitting without starting it I’m finding the battery is dead. If I leave it on a battery tender it’s ok

I’m trying to locate the parasitic draw. I’ve disconnected the negative terminal from the battery and measured the draw with my multimeter and am seeing between 400-800ma of draw.

I read a post on this site to measure the draw by disconnecting the ground thats connected to the body next to the battery above the passenger wheel well (near the fuze box). When I measure it there I see 30ma draw.

whats the best way to do this? Why would the two different measure points show such different measures?

Has anyone else measured parasitic draw and if so how did you do it?

@WranglerMan has a whole thread on how to measure.

If you don’t have a dashcam or other accessory, it’s safe to assume UCONNECT is the culprit. The manual even says to disconnect the power if the Jeep will sit.

I bet if you pull fuse F97 you’ll see the draw disappear.

Anyway, a tender is the correct workaround. I put mine on a tender a few times a month to keep the crappy AUX battery from draining the majn battery.

 

[WranglerMan]

@WranglerMan has a whole thread on how to measure.

If you don’t have a dashcam or other accessory, it’s safe to assume UCONNECT is the culprit. The manual even says to disconnect the power if the Jeep will sit.

I bet if you pull fuse F97 you’ll see the draw disappear.

Anyway, a tender is the correct workaround. I put mine on a tender a few times a month to keep the crappy AUX battery from draining the majn battery.

Mine is on a tender as I write this

 

[elf883]

you dont happen to have any obd2 programmer or reader installed do u ?

 

[Cali-JeepJL]

you dont happen to have any obd2 programmer or reader installed do u ?

i do. I pulled it out and the draw didn’t change much

what I was really curious about is why the draw shows 600-800ma at the negative battery terminal, but only 50-60 at the ground connection to the body (the recommended approach suggested in the other thread)

 

[Dave928]

do it at the battery. you need to be touching the post and the clamp before they disconnect so your meter completes the circuit without breaking the circuit. lock the jeep and set the alarm (with the hood open). let it sit about 30-60 minutes then check the meter (make sure the meter stays on). if it's over 100mA start pulling fuses until it drops. that's your draw.

 

[DanFelix]

do it at the battery. you need to be touching the post and the clamp before they disconnect so your meter completes the circuit without breaking the circuit. lock the jeep and set the alarm (with the hood open). let it sit about 30-60 minutes then check the meter (make sure the meter stays on). if it's over 100mA start pulling fuses until it drops. that's your draw.

Why the 30 to 60 minute wait?

 

[elf883]

Why the 30 to 60 minute wait?

it allows the system to goto "sleep" there are still active items running . like delayed lights and dash lights , and keyless entry systems

make sure if u have a keyless entry system to keep your key far away from the jeep as well , if not the jeep will always send a signal out saying its ok to open/run the jeep with key nearby

also make sure to push the hood switchs in and secure with tape or something , it will think the hood is still open

another thing instead of pulling the fuses u can try if you have one , a thermal imager gun - point it at all the fuses, it will show you a fuse that is warmer then the rest and this would be the first one i pull ..

 

[elf883]

hmm to better explain u can watch these videos
i do not remove the battery posts as the OP and many others do
i do it the way the first video shows - pulling fuses works, but makes the system wake up

 

[DanFelix]

Understood. Thanks for the explanation.

 

[guarnibl]

Does this approach still work when you're running multiple accessories off the secondary posts on the positive side of the battery terminal? I.e., if you run the clamp on the main wire, there's still other accessories running to the post that I figured wouldn't be captured on your clamp meter. Or is that not how it works? I suck with electrical but I'm trying to figure out if I have a parasitic drain vs a dying a battery (ESS no longer works and my CTEK shows battery dropping significantly overnight).

 

[elf883]

Does this approach still work when you're running multiple accessories off the secondary posts on the positive side of the battery terminal? I.e., if you run the clamp on the main wire, there's still other accessories running to the post that I figured wouldn't be captured on your clamp meter. Or is that not how it works? I suck with electrical but I'm trying to figure out if I have a parasitic drain vs a dying a battery (ESS no longer works and my CTEK shows battery dropping significantly overnight).

if you mean the 2 other spots on the main battery connection ,
it will not matter, it will detect the draw/drain on the battery it all gets drawn from the battery


where it will matter is the posts -- high current fuses on the fusebox " n1 through n8 "
i think its n1 that leads to the aux battery which goes to the ess , but dont quote me on that im not 100% sure of that
and i think n2 is the main battery

i had a lightbar i installed and the little lighted rocker switch (which stayed lit when off ) inside the cab, and was enough to kill my battery overnight and not start the jeep at all
the minute i figured out the draw , i removed the switch and it worked great.
i rewired a switch / relay setup for it and it worked perfect . never had any other issues

unless you have wired stuf in or have something plugged in that draws power , you may have a bad battery like others have had , or a bad ground/connection
have the dealer check your battery/s get it changed out

 

[guarnibl]

if you mean the 2 other spots on the main battery connection ,
it will not matter, it will detect the draw/drain on the battery it all gets drawn from the battery


where it will matter is the posts -- high current fuses on the fusebox " n1 through n8 "
i think its n1 that leads to the aux battery which goes to the ess , but dont quote me on that im not 100% sure of that
and i think n2 is the main battery

i had a lightbar i installed and the little lighted rocker switch (which stayed lit when off ) inside the cab, and was enough to kill my battery overnight and not start the jeep at all
the minute i figured out the draw , i removed the switch and it worked great.
i rewired a switch / relay setup for it and it worked perfect . never had any other issues

unless you have wired stuf in or have something plugged in that draws power , you may have a bad battery like others have had , or a bad ground/connection
have the dealer check your battery/s get it changed out

Thanks. Yeah it could be a bad battery but wasn’t sure about the clamp meter as far as where to place it since I had multiple posts. I suppose what you’re saying is it doesn’t matter. Clamp it around any of the battery power wires that connect to the battery and it’ll show draw from the battery irrespective of what power wire you clamped to.

But yes, I have a winch main cable going to a separate post, arb dual compressor and rock slice engineering steps. Other than that, interior has a tazer and pedal commander.

Could be a bad battery but wanting to ensure I’m using the clamp meter properly first. I’m not very experienced on the electrical side of things.

 

[elf883]

Thanks. Yeah it could be a bad battery but wasn’t sure about the clamp meter as far as where to place it since I had multiple posts. I suppose what you’re saying is it doesn’t matter. Clamp it around any of the battery power wires that connect to the battery and it’ll show draw from the battery irrespective of what power wire you clamped to.

But yes, I have a winch main cable going to a separate post, arb dual compressor and rock slice engineering steps. Other than that, interior has a tazer and pedal commander.

Could be a bad battery but wanting to ensure I’m using the clamp meter properly first. I’m not very experienced on the electrical side of things.

if all of them were wired correct and working as they should then you should have no issue ,
my guess is a bad battery, but this will let you know for sure and also get you more use to checking things out yourself and get to know how to check in the future
i know alot that never have tazer issues - and some that do
anything that plugs into the port will sometimes not let the system sleep
try unplugging it for a few days see if that helps
good luck

 

[Atreju]

When I leave my Jeep for 2-4 weeks sitting without starting it I’m finding the battery is dead. If I leave it on a battery tender it’s ok

I’m trying to locate the parasitic draw. I’ve disconnected the negative terminal from the battery and measured the draw with my multimeter and am seeing between 400-800ma of draw.

I read a post on this site to measure the draw by disconnecting the ground thats connected to the body next to the battery above the passenger wheel well (near the fuze box). When I measure it there I see 30ma draw.

whats the best way to do this? Why would the two different measure points show such different measures?

Has anyone else measured parasitic draw and if so how did you do it?

Do ever notice that the dash and radio are lit up even though the vehicle is locked and off, and you've not even touched the door?

My 2019 JLU MOAB had been at the dealership since 1-Sept-2023. The issue was that I was draining batteries every 3 to 4 weeks. The batteries would drain even though i drove my jeep daily.

The fix ended up being to replace the Sleeve Valve (PN - 52854755AB). It was causing my radio and dash to light up and then turn off over and over even though the motor was off and the jeep was locked. This constant on/off cycle drained and killed my main battery and then eventually the aux battery.

If you are suffering a similar issue of having to constantly replace your batteries you may want to have your Sleeve Valve (PN - 52854755AB) checked. It may need to be replaced.
The dealership only found it after a lot of trial and error.

I hope this information helps someone.

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