I seached but didnt find anything like what im seeing. On my 00 xj i was having battery problems, and found it was draining while off. Using my multimeter between the cable and the post i found just over a 2 amp drain. I replaced the battery because it wouldnt hold a charge, but need to find the source of the problem before i ruin the new one by deep cycling it.

What ive tried:
unhooking the alternator
removing every underhood fuse
removing every underhood relay
unplugging what i think is the pcm
disconneted the starter

right now ive narrowed it down to the bolt the positive cable connects to, that powers the underhood distribution box. Im certain its something that runs through the box that is killing the battery.

So, has anyone ever seen this problem before? I guess my question is what gets power from that box but isnt fused there?

 

Seems as if you've tried everything. Two suggestions:

1. I good long walk/hike, I find the exertion gets my brain thinking out of the box.
2. Follow the walk with a good nights sleep. At 2AM you'll wake up and think of something you didn't try, hopefully the answer.

Repeat as required.

 

I looked at the drawing and can't find anything. There are two cables from battery +, one to the starter, the other to the PDC terminal.
The PDC BAT terminal connects over to the GEN terminal, and also to a bus-bar inside the PDC that picks up one leg of the fuses. I don't see any sign of it going anywhere else.

Did you pull all the PDC fuses as a group or one by one?

 

Have you checked the vehicle for aftermarket accessories? I've seen many used vehicle that have something like an aftermarket alarm tucked under the dash but the owners were never given the remotes. The systems can sometimes become passively activated without the owner's being aware. Just because you weren't given remotes when you bought the vehicle doesn't mean there isn't something hidden in there somewhere. Also check for aftermarket audio equpiment- same thing.

Also, have you pulled fuses in the passenger kick panel yet?

 

Thanks for all the replies!

MtnHermit, thats good advice, and patience is something I'm thankfully getting better at!

Radi I've tried both, the last time over the course of about a week I pulled all the relays and just before then I pulled all the big fuses. I read the current draw after each pull/unplugging, and it stays about 2 amps. Individually I pulled all of the smaller mini fuses as well. I think tonight I'll pull every single one out of the box at the same time and read it again.

Cherockee, it is a former fire jeep so there definitely are some extra connections that were made. I haven't found anything left behind thats obvious, but I have no idea where they tapped into the wires for power.

Can anyone tell me if the PDC fuses "feed" the interior fuses? I kinda thought that any and all power going to that kick panel would go through a few of the PDC fuses. Ive pulled out some inside fuses as well, but not in a methodical fashion nor all at once because they're hard to get to and I dont want to end up not knowing where some go. I'll take a picture to keep it straight and then pull them all I think.

Its possible, maybe likely its not a new thing and I never knew about it before because the battery just held up for as long as it did.

 

Yes, the PDC fuses feed the interior fuse panel. It's called the "junction block".
Take a look around for power taps and fusible links. The few public safety vehicles I've had opportunity to work on had additional systems that bypassed the factory wiring...generally fusible links right off the battery. Radios, light bars, etc.

I found this drawing showing what each fuse and relay does....and swiped it. Perhaps it'll be useful:

 

Thanks! I'll save this diagram. I wonder what the "automatic shutdown" relay does.

So about the parasitic drain on the battery...

It seems that maybe there was some user error when it came to the multimeter... and I didnt notice or had reason to ever use the second jack that just so happened to read "10 Amps max" and the A to indicate that was for reading full amps... as opposed to the one that was for reading everything else, including mA and the like.

In my defense, the LCD did display A near the readout, so I assumed I knew what I was doing.

Thanks for all the help, and suggestions. In the end, the problem was me chasing a problem that didnt actually exist...

 

Power for Ignition and Fuel Pump run though it, allowing the PCM to kill the engine under certain circumstances.