Parasitic power draw on Jeep JK Wrangler

[sd455dan]

I have a a problem with the JK going dead in a few days if I don't keep it on a battery tender or run it. It has a LOT of electrical accessories - CB,Winch, 5 sets of lights, subs, touchscreen, air compressor, etc. Well I disconnected EVERYTHING aftermarket and still have the draw. Went through the factory fuse box 1 fuse/relay at a time with the meter between the neg. cable and the Neg terminal of the battery to monitor the draw. Stayed the same after pulling each individual fuse, one at a time.
Now I am baffled - I thought as I pulled a fuse, checked the meter I would see a drop in the draw at some point, and then know that is the circuit to chase. Didn't work - anyone have any suggestions on what I am missing?
THANKS

From left field...
Ran into a similar problem on a RAM truck, battery would go dead in a few days.
Every fuse and relay removed except the key off battery fuse.
Turned out the Horn button had shorted out years earlier. owner had removed the Horn fuse which would make you think problem solved.

nope.

The gauge cluster has a CPU in it that when things are working normally sends out check signals to the radio and Horn button after the vehicle is turned off. If no closed switch or draw is detected the computer goes into sleep mode , this reduces current draw to `~10milli amps.

Since the truck I worked on was detecting a horn button pushed, the signal the cluster CPU would never go into sleep mode. This resulted in a .5 to 1.5 amp continuous draw. Replacing the Horn button / airbag fixed the problem. It can also be disconnected at the actual button. The radio can do the same thing if it has a problem- basically the Cluster CPU detects a draw and then won't go into sleep mode.

FCA electrical architecture.:confused2:

Not sure if the JEEP uses the same type of system but i wouldn't doubt it also being FCA .
truck was a 2004 , model JK started production in 2006 ?

edit

As was posted earlier a bad alternator can have a draw thru the Alternator if an output diode is damaged.

When you said EVERY fuse has been pulled did that include the IOD (Ignition Off Draw) fuse?

also when doing a current leakage test needs to wait about 3 minutes to give the computer time to go into sleep mode if IOD fuse is still in circuit.

hope this helps , Good luck, electrical problems can be a hair puller.

 

[Oaktree]

FCA electrical architecture.:confused2:

I doubt this type of thing is unique to FCA vehicles. EVERY make controls every function thru one or more control modules. Even stuff (like your horn problem) that you wouldn't think would need to be.
Makes things a whole lot more expensive to fix if one circuit in one module fails, not like the old days when you could just replace a relay or cob something together to make it work.

 

[sd455dan]

I doubt this type of thing is unique to FCA vehicles. EVERY make controls every function thru one or more control modules. Even stuff (like your horn problem) that you wouldn't think would need to be.
Makes things a whole lot more expensive to fix if one circuit in one module fails, not like the old days when you could just replace a relay or cob something together to make it work.

No argument there but, Chryslers TIPM "Totally Integrated Power Module" has a history of troubles

Jeep actually recalled the Wranglers of 2007 model year for TIPM problems and there was a lawsuit , and a TIPM settlement

 

[CobyRupert]

Try these tests:
- Measure voltage across battery terms.
- Disconnect negative terminal and measure voltage between negative cable and and negative battery post. Is it the same voltage as across battery posts?
- Measure leakage current between disconnected neg cable and neg battery post.

 

[LouNY]

This is a negative ground system,
I would be looking for current draw with the ground connected and all the positive connects lifted and checked individually,
especially with your individual fuse test.

 

[Fuddy1952]

I'll try again...what IS the current draw in amps? Example: Are we talking about 200mA or 2 amps?
Thanks...

 

[Code54]

Basically 1 amp. draw

I will try the Positive side tomorrow and see if anything changes.

I will check on the recalls - another good idea there.

CobyRupert - I will give that a try tomorrow also. Always worth a shot.

Thanks for all the ideas everyone and will try and go down the list tomorrow after work and figure out what is going on.

Oh- the battery is a AGM battery and about 1 year old. The old one went dead and I replaced it (seems to be fine for a good while then this mess started)
I pulled all the fuses in the fuse box, and the relays when I did the neg terminal to Neg battery cable check - nothing changed so that is what surprised me.

 

[CobyRupert]

Disconnecting and measuring the leakage current at the negative or positive side shouldn’t give a different result.
But if disconnected on a the positive side & your meter probe accidentally touches the frame, hopefully meter has a fuse that blows or it gets smoked.
What I was getting at, is the voltage you measure across the disconnect should be exactly the same as across the voltage terminals. If not, cause of leakage points towards a diode.

 

[RBLapham]

Jeep has problems with the wires going to the starting motor corroding - causing the off draw. Clean the wires on the starting motor.

 

[Fuddy1952]

What others said is true, 1 amp draw would be same whether in series neg. or pos. lead.
I'd do this simple thing, since 1 amp draw even after pulling all fuses...
1) leave meter in negative side, showing 1 amp load
2) unplug one meter lead (one going to ground)
3) disconnect alternator (large wire going to battery)
4) reconnect meter: If still 1 amp draw, proceed to #5...if no draw, replace alternator
5) disconnect meter
6) disconnect large cable at starter motor which goes to battery
7) reconnect meter: If no current draw replace starter