Topic: A battery drain issue

[95yjman]

So this isn't a 4 banger issue but has to do with my 04 Jeep Liberty.  A couple months after I bought it, the tailgate on it would not want to open. (it opens with some kind of elecitrial crap in the handle) so in order to get it to open I would have to keep pushing the unlock button on one of the doors up front a couple times and then it would catch and I could open the tailgate. So shortly after that the power door lock fuse would just blow and you would have to open the doors manually and then of course the tail gate wouldn't open since the fuse was blown. It did this for awhile and still does this to this day.  I have owned the jeep since 2009 and then about a year or so ago I went out to start my jeep and it wouldn't start.  I replaced the battery I thought all was good, however the power door lock fuse would still blow every now and then like I said.  Now my wife and me work at the same place so we have been switching back and forth between vehicles and car pooling.  I have been noticing that the liberty does not like to sit for a day or two.  I would go to start it after it has been sitting and you could just tell the battery was a little weak on start up. However just two days ago I went out to start it after it sat for two days and the battery was drained enough that it wouldn't start but I still had dome lights and what not.  So we took the other Jeep that day and the liberty sat for two more days which left the battery completely dead.  I jumped it and took it to the local auto parts store and they tested the alternator and a battery and both came back fine.  Which leads me to my next question.  Is something with the power door locks causing a drain on the battery?  I did some testing with my multi meter however and couldn't find anything.  Here's what I did,

Here's the setting I had my multi meter on:

on that setting I had .141. I had the wife leave the tips of the multi meter on the positive and negitave battery terminals. I then went through and pulled each fuse and rely one at a time and we got no change. We had the negitive battery cable hooked up and had the positive battery cable off while we did this.  Are we getting some kind of draw with that reading?  What are we doing wrong?

I pulled the trim panel off the tailgate and check all the wires and connectors in there and all seemed well.  I didn't follow the wires through the vehicle though, that would require me to pull a bunch of pannels which if it comes down to that then i will have to do that. Anyway, any help would be great!

[sharpxmen]

you need to measure the current draw, not the voltage - so set the dial to amps, put the probe on the 20A, disconnect the + cable from the battery and connect the multimeter between the battery + terminal and the + cable with the red probe towards the battery terminal. You'll have some current draw due to the computer being connected, but that should be in the mA range so it might not show anything on the 20A setting. Anyway, a normal battery would drain fully for example in about 2 days if you have a 1 amp draw, at 500mA would take twice as long, you get the idea. I suggest you do this with the battery fully charged and then try to identify (like you did by removing fuses) to see when the reading goes down, it might be a circuit that is not connected to the fuse block like one that is connected via a fusible link or a PDC that has larger fuses and i don't know if the Liberty has either but something to consider.

and another thing, if your reading was .141v that means your battery was completely drained, you'll need to charge it to do this test.

[neale_rs]

Regarding the door lock.  I had some problems with the electrical trunk latch in a 2003 Neon and it turned out it just needed some lubrication. It's worth a try.

[95yjman]

Regarding the door lock.  I had some problems with the electrical trunk latch in a 2003 Neon and it turned out it just needed some lubrication. It's worth a try.

Would it drain your battery though? and cause fuse's to blow?

[neale_rs]

Would it drain your battery though? and cause fuse's to blow?

No, but those problems might turn out to be unrelated to the rear door.

[95yjman]

you need to measure the current draw, not the voltage - so set the dial to amps, put the probe on the 20A, disconnect the + cable from the battery and connect the multimeter between the battery + terminal and the + cable with the red probe towards the battery terminal. You'll have some current draw due to the computer being connected, but that should be in the mA range so it might not show anything on the 20A setting. Anyway, a normal battery would drain fully for example in about 2 days if you have a 1 amp draw, at 500mA would take twice as long, you get the idea. I suggest you do this with the battery fully charged and then try to identify (like you did by removing fuses) to see when the reading goes down, it might be a circuit that is not connected to the fuse block like one that is connected via a fusible link or a PDC that has larger fuses and i don't know if the Liberty has either but something to consider.

and another thing, if your reading was .141v that means your battery was completely drained, you'll need to charge it to do this test.

Hmm, I can't get it to show me anything, its all zero's.  I would think it would have to have something like you said..

[sharpxmen]

1. did you charge the battery? what voltage does it show, should be 12v to make the test relevant (if it's still .141v you won't get any current drain since the voltage is so low, although it would show zero if there was a short somewhere at that point)

2. if the battery was charged then change the scale to 1A or mA and see what's showing, there should be something like 10mA or in that ballpark for the car electronics that are powered at all times (computer and alarm, imobilizer, central door lock since you have a remote control)