niceguypmp3

ok, i put in a brand new battery and after 5 days of sitting it's completely dead! so now it's on a trickle charger. I think what i might try to do is once it's charged then leave it hooked up for a couple days or so and then hook up a multimeter to check for parasitic draw while the battery is hooked up and try to unhook the terminal carefully so as for the minivan to not lose voltage at all so hopefully then i'll find what's draining the battery after 2-3 days of sitting. If it ends up that i can't figure it out, i suppose we'll just unhook the battery when it sits which sucks. The van isn't worth paying a shop to try and diagnose what's draining it. I suppose i could unplug the alternator and see if that makes a difference too. I am just confused as to why it doesn't have hardly any parasitic drain for the first day that the battery is hooked up but then on day 2 or 3 it starts draining the battery... Any ideas???

mountainmanjoe

with careful measuring, there's no reason why you wouldn't be able to find the drain. I guess the trick will be catching it in the act. I guess you'll have to go and check the battery voltage often.

maddog0324

Something is waking up the BCM after you've tested for parasitic draw on day one. Does your rig have OnStar? My '04 Sliverado was giving me fits with a parasitic draw I couldn't find. I replaced the battery, thinking that was the culprit, but I still had to jump start it after sitting for 2 to 3 days. Since it wasn't my daily driver anymore, I cancelled my OnStar subscription, disconnected the battery and let it sit for about 2 weeks. I put a fresh charge on the battery, reinstalled it and drove the truck daily for the next 2 weeks to set the I/M monitors so it'll pass emissions inspection. After it passed inspection, I parked it and let it set. After 5 days, I went to start it and it fired up without lag or hesitation. I drive this truck about once a week now and I have not had a parasitic draw issue since. I hope this helps.

niceguypmp3

I think you are right and that it is something waking up the BCM. I let it sit a couple days and then carefully unhooked a battery cable while keeping contact with the leads of a multimeter on amp mode and it was drawing over 100 MA i noticed immediately. I started pulling fuses under the hood and none of them stopped it. I then opened the door to get to the inside fuse panel. This woke up the BCM and it drew over 1 amp for a number of seconds before that settled down but then it went down to 30 MA. I pulled the inside fuses one at a time and nothing changed. oh btw, no it doesnt have onstar. I am wondering if the sensor in one of the doors that turns on the dome lights and wakes up the BCM is malfunctioning and occassionally starts waking it up to which it draws over 1 amp for a bit. I'm afraid i will probably have to just put a remote battery disconnect switch on it so that it doesnt drain the battery anymore. I don't even know where i should look from here otherwise. Thanks for the ideas!

12three

i have an old vehicle with a parasitic draw... those little solar panels can do wonders.
i put one on the dash anytime i park a vehicle

sometimes when you first reconnect a battery and let a vehicle run its initial emissions stuff it starts saving a ton of info to its memory, even after you turn the vehicle off. that can deplete the new battery if you dont read the manual and follow the directions. i cant recall if uplander has a battery reconnect procedure, but that may be compounding your problems and throwing off your parasite test.
i have a ford that said to drive it or idle for like 15 mins after the relearn to make sure it didnt kill the battery.

i put the biggest battery i can cram in. it seems to solve lots of problems.

niceguypmp3

I have an update to my problem. Since getting the parasitic drain on the battery, i installed a battery shut off switch so that the battery doesnt go dead while it sits. We didnt drive it much at all afterwards and it has been sitting for around 6 months now. well, we needed the van recently to help move our boys into apartments and it's been in the 90s so pretty hot. Yesterday coming back from walmart, my wife said that suddenly the "charging system failure" messaged popped up on the DIC and she barely made it back to their apartments. Since it has well over 200k on it, and not knowing if its the original alternator, i am assuming the alternator went bad so, since it's not an easy thing to change on an uplander, i am gonna go tow it home today. I watched youtube videos on how to "easily" change it without dropping the engine like gm says to do but i dont know if i want to attempt it. Back when i did the parasitc drain test, i did unplug the alternator but it still had the drain so i figured the alternator was good. I guess if i replace the alternator, i'll leave my shut off switch on and see if the battery drains or not. maybe the alternator has been getting weak for a while causing issues. Why the heck didn't GM put the alternator in an easier replaceable location... smh... Sorry for reviving an old thread, but since i'ts an update, i figured it would be ok. If i get another update about this problem, i'll try to update further.

12three

I replaced my alternator in a couple hours. it is right on top, you definitely dont have to 'drop the engine'... i didnt even roll the engine.
that light came on in mine before i replaced my alternator as well. oddly the old alternator passed all the tests at the 4 different parts stores i took it to to get it checked after i pulled it.... i also replaced the ground lug right next to the battery when i did it. that factory ground lug looks ugly on almost every uplander i have ever laid eyes on... they look like they are barely making contact. the ground lug may have been the cause of the light coming on... its a lot easier to fix than the alt, so maybe try drilling/sanding out a new ground first...

the alt was easy though. biggest problem i faced was caused by me: i stripped one torx fastener for the wiper bc i could not find the correct-sized bit. i cut a slot in the fastener with the dremel and turned it into a slotted screw to 'fix' that...

annkeenan

Do you have the DVD player on the overhead rail? I bought this van used about a year ago and have repeated dead batteries. Alternator is ok and got new battery, but still happens occasionally. I have found the DVD player running when the car is off- all by itself- so I'd guess that it's the drain. I can't figure out how to get it off of the overhead rail and I'm about ready to beat it with a baseball bat!!!
Someone said to pull fuse #4, but I can't find the inside fuse box! The door inside of the glove box says Air filter access, so that's not it, but I'm not finding another access door and now I cant even get hood to unlatch. This is the weirdest car that I've ever driven. I push the latch ALL of the way over, but still won't unlatch. Argh!

maddog0324

The instrument panel fuse block is located at the right end of the instrument panel on the passenger’s side of the vehicle. Open the front passegner’s door and remove the cover to access the fuse block.

niceguypmp3

I forgot to come update after changing the alternator. That seemed to fix the battery drain problem that I had. After watching a couple youtube videos on how to change it, it wasn't too awfully bad. On the plus side, it gave me the opportunity to check the belt condition and check the idler pulley's which all seemed good still.