xjnm

Hi everyone,
After doing a parasitic draw test, I have determined that the 50 amp fuse "Battery ACC" in the power distribution center contains the circuit that is causing the draw. The draw is 150 milliamps and goes down to a very low number when this fuse is removed. I cannot find what is on this fuse though! Chilton guide only has one diagram for the pdc and it's not very helpful at all. I read on an australian cherokee forum that it may have something to do with the ignition cylinder, but no one seems to know for sure.

I would really appreciate if anyone knows what is connected to this fuse.


Thanks!

djgrayxj

Note from DJ
This Diagram is from a 99 hope it helps

djgrayxj

Note from DJ
You may also need this information.
Please keep us posted to progress or conclusion!

xjnm

Thanks a bunch for the info. So, I tried starting the jeep with that fuse pulled and the only things I could tell weren't working were the power locks and the cigar lighter/power adapter. It leads me to suspect a short somewhere in the locks since I was having this problem where it would engage the locking motors on all 4 doors sometimes when I shut the shotgun door.

Also, when I plug that fuse back in, sometimes one of the door lock motors actuates, I can't tell which one.

But what's weird to me is that the locks and cigarete lighter/power adapter are both fused in the kick panel fuse box, and pulling those fuses had no effect on my 150 mA reading...

I am pretty sure it's not the aftermarket radio (the PO couldnt solder and did these awful wiring jobs) or the CB radio since both of those being unplugged had no change to the reading.

I also think that if it were the locks, there would be a tear in the wire loom by the door hinge, but the plastic sheeting and the rubber boot is still covering all the wires so I have no idea how they would have gotten torn.
I'm gonna keep looking but if anyone else has some info that would be awesome!

xjnm

OK--- I fixed it! Looking at the first diagram that DJ posted, you can see that there is an unfused line and a fused line that come from the 50a fuse and go to the horn relay. I was missing fuse 21, and as soon as I plugged a new one in, the horn started to blare non-stop. This led me to think that there was a short in that circuit somewhere, and the only line that is fused only by the 50a and is connected to the horn is the one going into the horn relay. When I unplugged the horn relay, my amp draw dropped to ~0. So, I will replace that relay and all will be well-- and my horn will work!
Thanks again DJ for all the help!

BlueRidgeMark

Be careful with that - most folks who aren't well educated in electricity assume every problem is a "short", but that's rarely the case. Chasing a "short" can be very misleading.

A true short will usually blow fuses, not cause ghost draws. Now, a partial short can cause a ghost draw, true, but getting the "short" mindset can really blind you to other things which are more likely to be the real cause.



They can fray from constant flexing whether the boot is intact or not. It's quite common. Since you have a problem with the locks, I suggest you start there and examine those wires. Pull the boot back and take a good look.



By the way, Chilton and Haynes are not useless, they are worse than useless, as they often have incorrect information. They can have you chasing down the wrong trail, wasting time, and in the worst cases, breaking things. Throw it away!



EDIT: I see we cross-posted. Glad you found it. Sounds like that relay might have a protection diode built in, which can "leak". But it's odd that you had the leak with no fuse in that slot....

xjnm

Yeah, and you're right, it's not always a short. I was suspecting some kind of partial short inside a motor as well. It is odd, but the relay is connected directly to the 50 amp fuse (if I'm reading the wiring diagram correctly), not the #21 15 amp fuse, so if it was leaking or the relay had a short in it causing it to be stuck open/ horn stuck on, it would not be 50 amps, thus it would just draw power and not blow the fuse.

I hadn't thought about that with the door wires, so I may go through and check those just to be safe!!
Thanks for the help!

BlueRidgeMark

That's a common place for lock problems. That, and the switches themselves.

chitina

I'm having the same problem with the 50 amp battery acc fuse drawing power. This only started after I pulled the dash out to replace the heater core, and reinstalling the dash.

xjnm

did you check if it still draws power if you pull your horn relay? Otherwise try to check anything that you could've broken or any pinched wires or anything when you put the dash back in. Good luck and let us know!