Battery drain - repeated dead battery

[aufrex]

Within the past, several months, I've suffered several dead batteries, requiring jump starts. Initially, I replaced the original battery, however, the new battery also suffered the same problem. I took it to my mechanic, and he surmised that the alternator required replacement. However, despite spending $600 for a new alternator, belts, etc., the battery still goes dead regularly.

The Expedition has a feature wherein the radio and accessories (i.e. AC fans, etc.) stay on after turning off the key, but then turn off when the doors are opened. I suspect that this "feature" is no longer working - intermittently, and, if the radio or other accessories are on when I turn off the key, they stay on even after I open the doors.

Is this a computer programming error, or is there a fuse or controller which governs this feature? I have tried to break my habit of leaving the radio & accessories on when I turn off the key, however, old habits die hard, and I continually suffer dead batteries in the morning because something has been left on, or comes on after the doors are closed.

 

[GAINMOB]

the only accessories that will still be on is the power port on top of coin tray...that alone wont kill your battery...i guess u can manually turn off the radio to see if that does anything...not sure if you can change the setting or if theres a relay/fuse for it

 

[aufrex]

I've only come to the conclusion that it is the radio, by trial and error. The vast majority of the dead battery problems have occurred when I have left the radio on after turning off the car, and opening the doors doesn't shut it off (I surmise). Another thread, describing a similar problem, pointed to the GEM controller, located in the fuse/relay compartment. The poster solved the problem by banging the fuse/relay box and shaking the GEM unit - hard. Does the GEM controller control the radio/accessory shut-off? I guess giving it all a good, swift kick couldn't hurt?

 

[stamp11127]

Can't comment on the second gens, but in the first gens the radio isn't controlled by the gem.
Is your radio factory or aftermarket?

 

[aufrex]

It's the factory-installed, multi-disc CD with the DVD entertainment system. I have the 2004 Eddie Bauer Edition.

 

[nrbiss90]

Is your rear windshield wiper sticking? I had the same issue recently. The rear wiper motor would attempt to turn the stuck wiper "back to home" even long after the truck has been shut down. I disabled the rear wiper and the problem disappeared. A dead give away would be to open the rear glass. If the wiper motor cycles that could be the issue.

 

[tonydiv]

If you get a decent clamp multi meter you can easily measure the current flow while the vehicle is sitting.

Remember to disconnect the under hood light, or it will skew the results. On newer vehicles, you also may need to wait 10 or 15 minutes for the truck to really go to sleep.

Once you know how many milliamps drain you have, you can start doing diagnostics.
The easiest way would be to start pulling individual fuses and measuring the results.

 

[aufrex]

I had to repair the rear wiper recently, as it was stuck. I had thought the battery drain problem may have been related to the wiper (motor seeking "home" position, even though it was stuck), however, even after fixing the wiper, the battery drain problem persisted. I am convinced that it's the radio causing the drain, so, I am careful to be certain it is off before I turn off the key. I guess that's all I can do (except replace the GEM)

 

[Swetrid]

Ford has tsb for rear wiper causing battery drain.