Battery Drain

[donkeylips]

The other morning I went out to my car to find the battery dead (0 deg morning). I've been daily driving it for over a year and haven't had too many issues. Once in a while the car would crank slow, but now it has a 2A-3.1A battery drain. I believe a normal value is somewhere around .05A. So every time I park I have to disconnect the battery.
Also, I can't jumpstart the car normally. I have to disconnect the battery, charge the battery up, and then reconnect it.

This is a winter/year round beater. It's mostly stock with a lot of equipment removed, and it's seen tons of salt and corrosion. It idle surges like crazy and I've noticed a weird whirring sound with the engine note.

So I removed everything from the main engine bay fusebox one at a time:

The only one I didn't remove was the yellow corner one. But none of it had any effect. I did the same for the cabin fusebox. Still nothing. I'm wondering about this one:

I was able to easily remove the one on the right, but I guess I have to take the box apart to get the others out. I'll do that next. I wouldn't think the ABS would cause a problem since I've removed the control unit in the trunk, the main hydraulic unit, and all wheel speed sensors.

Assuming that doesn't do anything, what's the next step? Disconnect the starter?

 

[mitsuturbo]

Try pulling up the IOD connector. See if that makes any change.

If it does, start checking fuses inside the cabin.

 

[FlyingEagle]

^^^ after the above (and if no fault found), check to see if the diodes are on the way out (alternator).
Check for AC voltage across the battery terminals with the engine running.

Faulty diodes can create a short that takes down batteries. Possibility. Very quick check.

 

[dandanger]

Just had my alt changed because it didn't charge. At the same time my alt stopped charging, my battery also started to drain, like 5 amps(LOTS!), with almost all the fuses taken off. So I took my car back to shop where they changed the alt. Car was there like two weeks and they couldn't find the fault, yesterday got my car back and they told it was the new alternator which was draining the battery. So one vote for a faulty alt, even if it's charging ok.

 

[Struc]

Walked through that same excercise. Ended up being a bad alternator. Was draining a couple amps all the time.

 

[donkeylips]

Sounds like it's probably the alternator. This reman. alternator is probably not even a year and a half old. I hope I have some kind of warranty.
I pulled all the fuses that were bolted in and the only one that had any effect was the 100A ALT fuse. But this test was inconclusive because it broke the circuit and brought my reading to 0.00A.
I also removed the starter connection at the positive battery terminal. This had no effect.
I checked AC voltage across the battery terminals with the car running. I got a reading of 28V.
I didn't disconnect the alternator but I did disconnect the connector on it. I have no idea what this does, but it had no effect.

I don't know much about the IOD. Here is mine, am I missing anything?

 

[donkeylips]

Ok, I found the receipt. The alternator was purchased at Advance Auto 1/12/13. It says limited lifetime replacement.

 

[Pushinink]

I figured I would revive this old thread since ive used it as my 'goto' to trace down my battery drain issue that I think I may have finally resolved! I was having the same issues, battery would drain overnight, tested the alternator first, it checked out good. I narrowed it down to the room/radio fuse on the interior fuse block. well I didnt have any lights on and radio was operating normally. To make a long story short, the auto seatbelts are also on that same circuit. My auto seatbelts have a mind of their own and only work when they want to. So I unplug both sides the relay and the auto seatbelt mechanism behind the b pillar (make sure you unplug both or relay will still on) and so far so good. I plan to do a manual seatbelt swap in the future. I hope this helps some of you.