Battery Killer

[ynwa]

Hi. I've hunted around the forum a bit and I think I'm close. However, I always appreciate the group insight. I've killed 2 batteries. Stone cold dead. Driving fine for a couple of weeks, glow system good. No issues. Come home. Park. Check the van. .04v on the battery. The latest was a nice AGM. From my reading, it seems like a voltage regulator issue. However, I read a post that mentioned the Sense Wire and that it lurked around the fusible link. I noticed a disconnected wire in that area and am wondering if this is it?? Might I save myself an Alt pull? The wire is reconnected in the photo, but it was disconnected for who knows how long. If this is the Sense wire, it sounds like this will kill batteries if disconnected. Thank you as always!!

IMG_20200716_194559.jpg (100.71 KiB) Viewed 10682 times

[ynwa]

Okay, I've found that this is the AC lead, which was unplugged for a reason. I am still interested in the location of the sense wire. Sad story is that this van was one day away from landing on a new owner. :(

[deskinthewoods]

I had the same sort of thing earlier this year, "parasitic voltage drain".

You most likely have a ground fault...somewhere!

Hook an Amp meter up between your negative battery terminal and the negative lead. With all doors closed and lights off and key out of the ignition you should have no draw. If you do, there is a grounding issue somewhere. You can try to track it down by pulling each fuse and see if the draw stops. if not there, there are fusible links behind the battery. Try pulling each of those.

Mine turned out to be the alternator connection at the alternator which I accidentally found.

Here's my post: http://delica.ca/forum/viewtopic.php?f= ... 26#p141826

:)

[ynwa]

Hi, thanks for the tip. I was wondering about that, but I would have thought that the symptoms would be a little different. This was a catastrophic end to 2 batteries over a period of like a month. Dead, no recharging. Battery was fully charged in the morning for a drive (a week or 2 after the first one died under similar circumstances). Then after sitting for a couple of hours (or less). Dead, dead. Like no voltage. Less than 1 volt registering. It's bonkers!

I'll check for draw for sure, though.

[sk66]

Have you checked the alternator fuse? Have you tested the alternator's output voltage when running?
I highly suspect it's the voltage regulator/diode internal to the alternator and you are cooking the batteries. The sense wire would keep the alternator from charging, but you should get the warning lights on the dash. And if was a lack of charging things should stop working/running way before the battery gets down to 1v output.

[ynwa]

Hi, I meant to post this sooner, the issue was the voltage regulator. Most likely, as I replace the whole alt with a spare and all is well. Thanks for all the feedback.