dead battery after 1 week idle

[hikethemtns]

2003, 3500, 5sp, 4x4, 150,000 miles. After leaving vehicle set idle for a week the batteries are dead, placed a meter between battery post and cable BEFORE unhooking them, when cable is removed from from battery post i have 25 ma [1/4 amp] draw. Went to fuse box and pulled each fuse one by one and unhooked alternator and any accessories but current draw remains. Any help greatly appreciated. Jim

 

[Wingate]

Have you had the batteries load tested recently?

 

[wcjp]

Could be a slightly bare wire shorting to ground. Did you pull all relays? Sounds like your problem is before the fuse box.

 

[sag2]

250 mA is a quarter of an amp. At 25 mA you are fine, that is a normal draw after several minutes. You must have something that is waking the BUS up and drawing several amps for a period of time. Roll down the window so you can check the interior for lights on, or trip the door latch or close the door switch and leave the door open and check the draw again watching the meter for a couple of hours. Hopefully you have a meter with min/max setting so you don't have to watch it. When the Bus wakes up it should draw a couple of amps for about a minute and then go back to sleep, dropping off until it gets back to 25 mA or so. With dual batteries fully charged you should be able to last a week easy with a 60-70 mA draw.

 

[Hoefler]

How old are the batteries?? With temps getting colder, batteries that are older can start having problems. Have them tested, you most likely have a bad one or two. Replace them in pairs.

 

[HBarlow]

If you're still using the OEM batteries in your '03 that experience was probably giving you a clue it's time to replace them.