'97 Grand 4.0. Can't sit for more then a week before battery is dead. Sears and an independent garage all say "no drain found". HOWEVER, the current mechanic says, after 20 minutes on the tester (others only test for 10 seconds) , something happens and there is suddenly a small drain. They say, put in a kill switch vs. a long and expensive diagnosis w/expensive parts (BCM, computer...). I say, I wouldn't put a bandade on cancer - fix it!!! Been in the shop for a week. Anyone have continually dying batteries?

 

I pull each fuse, till the problem is (hopefully) isolated to one circuit

This could get expensive if ur paying shop time

I would do this myself, and fit an isolation switch in the meantime

current draw on a DVM should be <30ma, and not enough to make a test light glow

 

Bah

 

this is common on jeep zj's if you pull the 50 amp fuse out of the power dist. box i think it is marked aux trail tow you will have no dash lights but most times prob will be fixed. is anything not working like door locks mine was the door lock in the rear hatch unplugged it and stopped the battery drain it is most times something in rear hatch wiper motor door lock etc. if they are not working the bcm will not go in sleep mode and it drains batt

 

THAT WAS IT!!! A faulty cut-off switch in the rear hatch (disables the wiper if the window is open) was stopping the BCM from going to sleep...a very small slow drain, but would kill a parked (for 2 weeks) battery. No previous mechanic found it because it had to be hooked up to the meter for 20 minutes for it to trigger, and they would just hook & look, so saw nothing!!!

 

Went around with this myself few years back. Yes the hatch open switch will do it, there are also the key switches. Mine was both key switches on the front doors, drivers went first. They are also different right and left and marked on the back with R or L. I had an ammeter set up to watch it go to sleep and could see the 40or so mA drain (I forget how much it was but way too much, when it was fixed you could watch it cycle down to 14 mA after a minute or so.) Also the alarm would not set, the red light wouldn't flash, and the interior lights would stay on. I called a dealer service guy was nice enough to say they had lots of problems with the door switches. They stick in the open position and the bcm thinks the car is being unlocked. Tested it and sure enough. Junk yard had tons of them and switched it out. Been fine since alarm sets every time. Changed both front door switches and hot wired the back hatch switch rather than mess with it.