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'01 EX, DEAD battery overnight, again

4262 Views 6 Replies 4 Participants Last post by  Dirkdaddy
Well, it happened again . . .

Van's battery (1.5 years old, and I top it off with an off-board charger every so often) is DEAD (2.4V) overnight. This happened 1.5 years ago as well when we replaced the battery just in case.

I have identified a common element in both cases: the van was parked with the doors locked for a day or longer without being driven. Then my wife used the remote to unlock doors to get something out of the van (first time, just the rear hatch, yesterday, the side door), did not start it or drive it, used the remote to lock the doors, and then the next day, battery completely dead (not 11.9V dead, so dead that no interior lights come on at all, not even dimly).

Whatever it is that is draining the battery, it is more than a few amps. A 1-2 amp draw will not bring a fully-charged battery down to almost zero volts overnight. So it's not a light bulb stuck on somewhere, I know that, and it wasn't the interior lights on either (we would have noticed those).

I am wondering if there is something wrong with the power locks or security system which is keeping something turned on when the 'lock' button is depressed on the key fob (like instead of just pulsing the power lock circuit, it keeps it on continuously).

It's maddening as it seriously reduces my confidence level in the vehicle. And what are my chances of finding the problem, when it has only happened twice in 1.5 years???

Anybody got any ideas? I have already purchased a datalogging Fluke multimeter for recording battery drain current for a similar problem in my 2001 Buick Lesabre (also has intermittent overnight battery-killing gremlin). Doesn't help much unless you can catch the problem in action, and then you have to pinpoint the exact source of the current drain. Arrrgggh!
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Do you leave the headlights in the on position all the time as I do and let the timer turn them off? Do you press the lock on the remote the second time and listen for the horn beep to verify the doors are closed? If the headlights are in the on position and a door is not completely closed the headlights will not time out and turn off and they definitely will kill the battery over night. Since you have the same problem on two different vehicles I would be looking at all operating procedures.
Just make sure none of the overhead lights are on. Even if only one is on, it will drain the battery overnight. I'm in the same situation...every year or two my battery gets drained overnight because one of my kids left the overhead light on. My van is on its 11th year of service and I just replaced my second battery. The first two lasted 5+ yrs each.

'00 EX-Nav
Nope, I always turn the headlights off by myself. And I'm sure that it's not any of the interior lights, I am well aware of that issue.

Neither my wife nor I typically hit the remote lock button twice to honk the horn while locking, does this make any difference?
It vrifies all the doors are latched and alarm is armed.
Update (I just added this same info in a similar thread): I suspect a sticking air conditioning compressor clutch relay. My sister's '99 Ody had this issue (killing a brand-new battery) and by luck my BIL happened to catch it while the relay was stuck so was able to find it.

I haven't replaced it yet but have it on the parts list for the next time I make an order.

We have had a couple of near-total-drain overnight incidents which we have traced to leaving the aftermarket rear-seat DVD player turned on, but that has a much lower current draw than the A/C clutch coil does.
Realize old thread but IMHO its better to link to existing threads on same topic.

I was looking at a friends van that has this battery drain overnight issue. His power doors are shot, that was my first guess so I removed the fuses in pass. footwell #1 and #5, testing it now. There are so many systems that are "ON" when the van is "off" makes troubleshooting a current drain more difficult. I used a digital multi-tester with a 10 amp capacity (very cheap HF model) through put, tested key off draw through between battery cable I removed and the battery post, at first I got like. .4 amps then it settled down to gradually to .1 or .07 amps. But that was after I removed the fuese. DId not have a lot of time to devote to it. any suggestions. Need to test obviously with the fuses back in and see what current draw there is.
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