Parasitic power draw on Jeep JK Wrangler

[boatmoter]

problem with testing for a drain on the later model vehicles, it takes a about 20 minutes for the modules to go to sleep . when you disconnect the battery to hook the meter or test light,the modules wake up and pull voltage, throws your testing off, I use a jumper lead and connect it between the neg post and neg cable, let it sit 20 minutes with everything off,the modules are a sleep by then, then hook your meter up before you remove the jumper lead, then you can get a accurate draw test, I usually use a digital inductive clamp for DC voltage so I don't disturb the modules.. Bob Dillon is right.. the times,there are a changing.. I miss working on the 60's & 70's cars, before I retired the newer cars were driving me nuts.. good luck, also,if you have a radar detector or anything like that plugged into your power point, it may cause a drain,ran across that many times

 

[groundcover]

Wonder what this will turn out to be. My 2014 seems to have the same issue if I let it sit a few days. Replaced the battery and it has done it a couple of times since.

 

[Doofy]

The Wife's 2002 Jeep Liberty does this after sitting for 2 weeks. I just disconnect the battery terminal. Eventually, I will install a disconnect switch. It is not worth my time and effort trying to find the real problem. Been there and done that on my Ranger. Waste of time.

 

[boatmoter]

another test you can do is disconnect the main battery wire at the Alternator, if the problem stops, then you have a diode in the Alternator leaking down which will cause a drain, will still charge ok,but will have a drain, I have also had customers have their dome lamp switch on and the dome light was causing a drain

 

[Doofy]

another test you can do is disconnect the main battery wire at the Alternator, if the problem stops, then you have a diode in the Alternator leaking down which will cause a drain, will still charge ok,but will have a drain, I have also had customers have their dome lamp switch on and the dome light was causing a drain

I had a glove compartment light staying on too. Also, you have to be wary of the hood light mercury switch on some vehicles.

 

[Fuddy1952]

Do you get the same exact VOLTAGE from the disconnected battery cable to the disconnected battery post, as you do across both battery posts?
You should, except for very unique circumstances. Test results will eliminate or confirm circumstances.

That test you have to know the meter. Some modern digital ones may have 11M ohm/volt input impedance so a small load won't affect voltage reading, an older, say, 1K ohm/volt meter way different results.
One draw test is series a test light with ammeter across battery. Then you know what test light draws (say, 250mA or 1/4 amp). Then use a headlight same way (say it's 2 amps). Then just clip in (series) headlight with battery cable to post. A 1 amp draw headlight would be on but very dim. Disconnect things...when headlight goes out you've found the draw.

 

[Code54]

I been leaving a trickle charger on it and of course that is working great. I have pulled the alternator power cable from the alternator and no change. The only thing I can get it to drop is if I pull the big fuse for power off items (cant think of the name) and then of course it drops. I am pretty sure it is in the actual Jeep somewhere. I know I have two open recalls, one for the airbag of course so I am hoping that when they do that maybe it is in there?? Ok, I know I am wishful thinking but what the heck.. cant hurt to hope right? LOL

 

[DaveMueller]

1 Amp is a LOT of resting current. All of the microprocessors together should only be a few tens of milliAmps, 100 mA at most.
There are also things that aren't fused but have 12V all the time, they'll have a fusible link somewhere to the + terminal.
I was going to suggest a courtesy lamp in a closed compartment but that should go away when you pull the fuses.

 

[Code54]

I thought the same thing. I even went out at night and checked for a glow anywhere in the jeep to see if a light was showing that I somehow missed. Was thinking intaking my thermal imager over and just "looking around" inside and under the hood and see if I see hot spots. Sometime that little extra heat pops out and help figure out that is going on.

 

[Doofy]

I thought the same thing. I even went out at night and checked for a glow anywhere in the jeep to see if a light was showing that I somehow missed. Was thinking intaking my thermal imager over and just "looking around" inside and under the hood and see if I see hot spots. Sometime that little extra heat pops out and help figure out that is going on.

This is why I install Battery Disconnects on all my vehicles, even the Tractor. I don't care about radio presets or computer re-learning. I just flat out hate dead batteries. Also, nothing will short out and burn the garage or barn down if it is disconnected.