1998 Grand Caravan Battery Drain
 

I had just recently purchased my Caravan and after installing a car alarm and aftermarket stereo/amp/speakers, I have been having a parasitic battery drain. I don't know if the battery drain was present before I put in the alarm and stereo, but I used a multimeter and tested the fuses and see that the draw is coming from the EATX fuse. With the fuse in, I'm drawing near .08 amps, and without it, I'm drawing .01 so it's definitely the EATX fuse. I have done some research and found out that the EATX fuse has to do with the transmission. Something I never touched. So what should I start looking at to fix this battery drain?

Something that may be related is that my shifting stick (don't know what to call it) but the lever that changes gears from park/neutral/drive/reverse has a slight issue going into park, so you have to make sure it clicks into place. Could this be part of the issue?

Thanks in advance!

Could be in the PDC, remove the EATX relay and see if the draw is gone. Its called an autostick. Also remove the 60 way connector if needed. Sorry at the EATX module.

Thanks for taking the time Master Tech!

I have removed and replaced the EATX relay with a different one in the same fuse box, and still had the same draw. I took out the driver panel and don't see any sort of electrical connection to the autostick, so now I'm starting to think it's a deeper electrical problem.

Where is the EATX module located?

Under the hood on the right inside fender.

Thanks, I'll check it out tomorrow and update.

Ok so I found the EATX module. Took off the connector with the whole mess of wires, and after I took that connector off, the draw does go below .00 (my multimeter can't read below that) so it's definitely the EATX module.

I have a 96 grand caravan that I'm about to junk, would I be able to just swap out the modules? Or does it have to be a specific type? Is it dependent on the engine type? (3.8l)?

I also checked prices on ebay, and they run around $95 - $110 Used, which model do I choose? My car is a 1998 Grand Caravan SE AWD, 3.8

Thanks in advance!

Ok, so ignore my last post, I found out answers to my questions.

So I did some more troubleshooting and I used the TCM from my old 96 caravan, which I know is a different model but I only wanted to see if it still drew current from the battery. And sure enough, I was still drawing .09 from the battery with the 96's TCM. Which leads me to believe that the original TCM is fine, especially since I'm not experiencing any transmission/engine issues. So now I'm lost at what could be draining. It definitely has to do with the EATX/TCM circuitry, but where?

BATTERY IGNITION OFF DRAW (IOD)
High current draw on the battery with the ignition OFF will discharge a battery. After a dead battery is serviced the vehicle Ignition Off Draw (IOD) should be checked. Determine if a high current draw condition exists first check the vehicle with a test lamp.

Verify that all electrical accessories are OFF.
Remove key from ignition switch
Turn off all lights
Liftgate and glove box door is closed
Sun visor vanity lights are OFF
All doors are closed
Allow the Illuminated Entry System to time out in approximately 30 seconds, if equipped.
During Transmission Control Module (TCM) power down there will be 500 milliamperes present for 20 minutes. Afterwards less than 1.0 milliampere.
Disconnect battery negative cable Disconnect Battery Negative Cable
CAUTION: Always disconnect the meter before opening a door.

Using an multimeter, that has least a milliampere range of 200 mA. Set meter to the highest mA range. Install meter between the battery negative cable and battery negative post Milliampere Meter Connection Carefully remove the test lamp without disconnecting the meter. After all modules time-out the total vehicle IOD should be less than 25 milliamperes. If ignition off draw is more than 25 milliamperes go to Step 4.
Each time the test lamp or milliampere meter is disconnected and connected, all electronic timer functions will be activated for approximately one minute. The Body Control Module (BCM) ignition off draw can reach 90 milliamperes.
Remove the PDC fuses:
Interior lamps
Brake lamp
IOD
If there is any reading, with fuses removed there is a short circuit in the wiring. Refer to wiring diagrams. If reading is less than 25 mA go to Step 8.
Install all fuses. After installing fuse, the current can reach 90 mA. After time-out the reading should not exceed 25 mA. If OK go to. If not, disconnect:
Radio
Body Control Module
Remote Keyless Entry Module
Disconnect one component at time, to see if any component is at fault. If the high reading is not eliminated there is a short circuit in the wiring. Refer to wiring diagrams.
Remove interior and brake lamp fuses. Install the fuses. The milliampere reading should be 2-4 mA. If reading is higher than 4 mA:
Disconnect PCM.
If reading is OK, replace PCM.
If reading does not change, disconnect the TCM.
If reading is OK, replace TCM.
If reading stays, there is a short circuit to one of the modules. Refer to Wiring Diagrams.

Here is what i use. This is from a mopar manual.

Wow, that sounds about right with why I was testing the EATX and it was drawing .09 amps, so I guess maybe that isn't the problem, I just had to wait till it powered down.

I will follow these steps and update, thanks a bunch master tech!!

If all else fails, a battery disconnect switch can be used, some even having remote control functionality. A couple of sites with info on battery disconnect switches follow.

http://www.watsons-streetworks.com/battery.html

http://www.secondchancegarage.com/public/676.cfm This one is referred to as the "Battery Brain", and shuts off automatically when excessie battery drain is detected.

"The idea behind the Battery Brain is simple: electronically monitor battery voltage and prevent its discharge beyond a certain "safe point." Its internal circuitry isolates the battery from energy drainage, whether it is due to lights or other electronic devices left on or a faulty relay or alternator in the car."