ElSapoRojo
New member
So bringing life to a dead post here. Im having a 70mA draw on my battery. This is after i have pulled #7 fuse. Is this to much of a draw? Needing to figure out if the drain from #7 is my only problem or not.
MUX/T TOW fuse draining battery
- Thread starter RCJP
- Start date
Yes way too much of a draw. After your Body Control Module goes to sleep, you should have less than 10ma, if I recall right. If you dont understand what the BCM does or how it works, you need to learn that ..First, may I ask a couple questions ...does your jeep have the red LED type light on the dash that is supposed to flash when the alarm system is armed?
ElSapoRojo
New member
Thanks for the reply. Yes. 96 jeep GC limited. When ive tested it doors are closed but alarm off. Hood light unplugged. I know what the BCM is thats why ive pulled that fuse. Unless there is a second fuse? Is the BCM a dual system possibly?
OK, if you answer my specific questions that will be a start. They are:
Are you able to set the alarm at all, either by key or by hitting the door lock switch on the door?
Does the light flash on top of the dash indicating it is alarmed?
With the alarm set, when you enter the drivers or passenger door, do the interior lights come right on when you turn the key in the lock?
If any of the alarm or interior light functions are not working exactly as they should, you are likely on the right path and the problem will lie either in the drivers or front passenger door lock switch on the back of the lock cylinder, or the rear hatch detector, rear window detector switch, or the 4 door open switches. (My case it was the drivers door lock cylinder switch, broken in the unlock position, making the BCM think someone was trying to legitimately enter the vehicle with a key. You can pay $40 for these or scarf them at a bone yard for almost free.
Check them with an ohm meter to make sure they work when you turn them, and don't get the left and right sides mixed up.)
If the alarm or lights aren't working as they should, what you can do is back up and read the BCM wiring diagrams and posts in this thread, there is a wiring diagram showing where each of the lock switch wires come in, lock switches, hatch, rear glass, and door switch wires. Then, at the BCM harness, (it's the smaller connector that you can unplug without taking out the BCM,) one by one, using the diagram, cut and reconnect the little copper wires for the circuits you suspect and see what effect that has on the current draw. In this way you can isolate the problem. Is what I did. When you disconnect the right one the bcm will time out after about 40 seconds and you will see the current drop to very little, about ~10ma.
Really helps to have a good adjustable flashlight to spotlight this while doing it.
There is also a small fuse by the passenger feet under the dash in the fuse block that is more specific to the interior lights.. this may or may not help you. Mine, 1997, does not have the under hood light at all but that should make little difference, just another check at the bcm harness.
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ElSapoRojo
New member
All lights function. Alarm works. Only thing strange is i can set the alarm when the driverside door is open. And sometimes the lights dont come on when the driverside door is open. With any other doors or hatch open alarm wont set and lights work as they should. i will try what you suggested this weekend. When i have daylight to work by. Thanks again
Yeah man, from what you describing, I would be looking at the switch on the back of the drivers door lock. The dealer service guy even told me there were a lot of problems with these.
When the car is alarmed and locked, when you put the key and the driver door and turn it counterclockwise, the interior lights should all come on, even the overhead ones, and the little circle around the ignition. They then stay on until you put the key in the ignition and turn it, even if you enter the car and close the door.
When the car is alarmed and locked, when you put the key and the driver door and turn it counterclockwise, the interior lights should all come on, even the overhead ones, and the little circle around the ignition. They then stay on until you put the key in the ignition and turn it, even if you enter the car and close the door.
Yeah if its like you say above, then is sounds like the driverside door light switch isn't opening, thats the one on the door jamb. Simple to take it out with phillips head and see or fix/ replace.
TonySaprano
New member
(97 JGC)
Bookmarked this thread
I just joined Jeepz because I found this thread and I had to join, And Thank everybody! who posted such great info
on this parasitic drain problem. I tried using the Voltage drop method across fuses but I could never get the meter to show it.
I had a .240ma draw and I pulled the 50amp. Yep, that was the circuit Next, I pulled fuse cb2 20a. Draw dropped down to .053ma. I then installed the cb2 and then pulled fuse 7. Bingo ! I put fuse 7 back in and waited for the BCM.
The current draw stayed at .053. Fingers crossed and running the engine to charge the Bat.
When the current draw stayed steady at .053. I can only figure out that a fuse connection problem or the BCM reset.
If that's possible? Anyway, Fingers still crossed and will monitor the Bat for a decrease in Volts. to continue investigating
Once again, Thank you Jeepz and Thread Posters for making my life easier
Bookmarked this thread
I just joined Jeepz because I found this thread and I had to join, And Thank everybody! who posted such great info
on this parasitic drain problem. I tried using the Voltage drop method across fuses but I could never get the meter to show it.
I had a .240ma draw and I pulled the 50amp. Yep, that was the circuit Next, I pulled fuse cb2 20a. Draw dropped down to .053ma. I then installed the cb2 and then pulled fuse 7. Bingo ! I put fuse 7 back in and waited for the BCM.
The current draw stayed at .053. Fingers crossed and running the engine to charge the Bat.
When the current draw stayed steady at .053. I can only figure out that a fuse connection problem or the BCM reset.
If that's possible? Anyway, Fingers still crossed and will monitor the Bat for a decrease in Volts. to continue investigating
Once again, Thank you Jeepz and Thread Posters for making my life easier
Re: MUX/T TOW fuse draining battery - solved
The same problem appeared on my 98 Grand Cherokee 4x4 4.0L 6cyl
I could trace it to the tailgate glass switch. The crimp on that switch weakened so that closing the tailgate glass would not always make the connection. I removed the switch, pressed it back together and clamped it in a vise. I then carefully crimped the aluminum skirt back down with a (light) hammer and screwdriver. After confirming the functionality with a multimeter (ohms setting and operating the switch), I reinstalled the switch, tested the functionality on the car and put all the trim back in place. The problem is gone ever since.
Hope that helps all those with this pesky issue out there
Pebeus
The same problem appeared on my 98 Grand Cherokee 4x4 4.0L 6cyl
I could trace it to the tailgate glass switch. The crimp on that switch weakened so that closing the tailgate glass would not always make the connection. I removed the switch, pressed it back together and clamped it in a vise. I then carefully crimped the aluminum skirt back down with a (light) hammer and screwdriver. After confirming the functionality with a multimeter (ohms setting and operating the switch), I reinstalled the switch, tested the functionality on the car and put all the trim back in place. The problem is gone ever since.
Hope that helps all those with this pesky issue out there
Pebeus
its not the maxi fuse its a fuse inside the interior fuse box think its number 7 pull it out and it will remove the 50 fuse short i just rigged a relay into that fuse so when the ignition is cut off it opens that fuse and poof no more short its a lot quicker and easier than trying to figure out which door or window switch is bad keeping the bcm active draining the battery pull the fuse and your short will be gone
WOW!!! 10 years since this post..and I still get notifications.. Have 3 kids, and I am now living in Alabama... but NO Jeep
. ....I remember taking almost the dashboard appart looking for the issue. it turned out to be the trunk switch.
what made it difficult to find is the fact that that switch will NOT turn the dome light if open. first thing I checked.
hope this post keeps helping people
:shades:
greekmechanic
New member
Hello everyone.i read all the posts,i am from greece i have in my shop a jeep grand Cherokee 98 v8 with the same symptoms of battery drain..fuse 7 and cb2 have all the current...i read for the switches, i removed all and the locks and rear lights and everything i believe and i can't stop it, i am very confused..my question is what exactly needs the bcm, ddm, pdm to sleep?the car haven't a alarm and the locks have only 2 wire no switches.another thing is that haven't the code for the radio but i believe that isn't a problem,iam right?thanks a lot any ideas are welcome
JPNinPA
Well-known member
So if you placed the current meter in the ground side of the battery. Then pulled fuses until you found fuse 7 and CB2 with the high current.
Which fuse block was fuse 7 in ? And is CB2 a fuse or a relay?
Never look down on anyone unless you are helping them up - Jesse Jackson
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jacklee
New member
It sounds like you really know your way around the alarm system and BCM wiring thanks for breaking it down so clearly. Your step-by-step method of checking each switch with an ohm meter and isolating the circuit at the BCM harness makes the process much easier for anyone trying to track a battery-drain issue.
If someone is still stuck even after going through all these checks, getting the car inspected at a bugatti service center dubai can also help, especially for complex electrical faults. But your explanation is a great starting point for understanding where the problem might be.
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