This is more of an info post, rather than a question post. Other people may run into the same thing and think it's some big electronics problem. I don't think it's an electronics problem at this stage of the game, but I'll see how it behaves over the next few days. I bought this 2009 Uplander 3.9L a couple of years ago from my parents. They bought it new. It has 178,000 kms. on it. Mom is too old to remember if this thing ever had a
battery put in it. It has a AC Delco batt in it instead of an off brand, so it could be original. That would be pretty good getting 10 years out of a batt. So, my daughter drove this thing home from work the other night and parked it in the driveway, nothing out of the ordinary, it started fine at her work, drove fine, whatever, all was good. My wife gets in it the next morning to take off, and the thing won't crank. She turns the key and the horn blows once, click under the hood, door locks go crazy, and nothing else happens. Radio works, headlights are reasonably bright, I didn't really check anything else because it was pouring rain. Wife then tells me that lately the theft alarm has been going off after she locks it with the door panel button, closes the door and starts to walk away. She gets 10 feet away, and the horn starts going. She has to unlock the van and get the key in the ign. to shut it off. The remote on the key fob won't do it. As a side note, the key fobs weren't working for quite some time, so I did the 'put the tin foil on the insides of the buttons' trick. Thinking that maybe that tin foil slipped around in there, I took it all out yesterday. I don't know where we are with all that just yet, the next few weeks will tell. I came on here to get some ideas, and people are talking about the anti theft system getting turned on by mistake, or after
battery replacement the anti theft got turned on, etc. I read about putting the key in the ign, try to start, then let the key spring back to run position for 10 mins., shut if off, then try to start. So I ran out in the rain to give it a shot. So I'm sitting there with the key in the run position, and I'm playing with the dash info, and I notice the batt volts are at 8.8 and dropping. What the? it drops to all the way to 8.0v. Alright, there's the problem, the batt is toast, good enough. The rain let up yesterday, so I go to check this thing out a little more. Use a voltmeter to check right at the batt posts, and there's 12.2 volts in it. What the? I should've checked the volts at the clamps to see for bad connections, but it slipped my mind. I was expecting to see something a lot lower than what was there, so it threw me off a bit. I try to start it, no horn blow, door locks are fine, and it cranks over once, then done. I put a booster pack on it, and it fired right up. Charging at 15v according to the dash. Let it run for about 5 mins, shut it off, and it starts right up again on its own, no booster. Took it for a 10 mins drive, got home, it starts right up 5 times. Now charging at 14.2v. So at this point I'm not sure if its a bad batt or a bad connection at the batt. All the posts look clean and also the main feed that goes to the fuse/relay box, but I take everything apart and clean them all. Put a
battery charger on for 6 hours, and then let it sit over night. This morning the batt is at 12.8 with voltmeter. It starts right up and was charging at 14.4 on the dash. I sit there and rev it up for a bit and watch the dash reading drop to 12.6v, hmmm, so I turn a few loads on to see if the alt will respond, and it did. Headlights, rear window defog, and blower on high, and the alt brought the dash reading back up to 14.4, so thats all working. I think at this point I'm probably looking at a new battery, there's probably a cell going bad in there, but I'll drive it myself for a few days, carrying my booster pack around, and see what it does. What was throwing me at first was the horn blowing, and the door locks going nutz while trying to start it, but when batteries are low, all kinds of stupid stuff starts happening because all the computers and modules can't talk to each other properly. Also, not sure how much parasitic draw is on the batt while sitting. It's supposed to be no more than 50 milliamps if I remember, but at this point I have no way of testing the actual parasitic draw. I have a clamp on ammeter, but it will only do AC, not DC. I'll look through all my old digital meters to see what I have that will work. Sorry this is so long, but I wanted to give detailed info for the next person having similar findings. I'll post back here in a few days to say if anything changed or if I buy a battery for it.