Also is there a regulator on the battery/alternator, I assume there is but could not find it.

 

On another car I used to own, regulators were a common problem and if your battery drained it was a good idea to ''feel'' the regulator to see if it was warm.

If warm, it was broken.

Not sure if it is the same setup on a Subaru, but most probably is.

From what I am told the alternators are pretty sturdy and do not die too easily, always pays to check the regulator first.

 

Thanks

Edited December 11, 201312 yr by subaruneedpdf

Let it idle on its own until the radiator fans kick on and off once. Stop the engine, wait about 30 minutes (wait an hour if its a really hot day), then restart, let it idle about 5 minutes or until the fans come on again, then go for a short drive. It's best if you can get up to about 50-55 mph, but not necessary.

 

This method works for almost every car I've worked on to get the ECU to learn idle and driving air/fuel settings. It also relearns spark timing, and transmission shift points if you have an automagic.

I see many people posting at times saying after a new battery the car will stall.

This happens to me everytime I disconnect the terminals as it must reset the computer.

This could mean the ECU has been operating at its limit of ability to adjust the car's A:F ratio, and timing. Which means you may have some bad sensor, a vacuum leak, an exhaust leak, bad knock sensor or other issue.

 

And the current regulator is inside the alt.

Edited December 12, 201312 yr by 1 Lucky Texan

I had almost the exact same problem as the OP. I have a 2005 Legacy GT, and about 9 months ago I started seeing my battery go dead after a few days of not driving the car. I replaced the battery, which was a few years old, but then the new optima battery started to have the same behavior.

 

Around the same time, my factory CD changer got jammed and I just figured I'd live with it until I got around to fixing it.

 

This week I got tired of the battery draining problem and found this thread - thank you all for the great suggestions!

 

Checking all of the fuses showed no major culprit - current drain with the car off stayed about .7 amp. I pulled the stereo out, and like magic it dropped to .02 amp (20 mA).  Apparently, the stereo is not on one of the fuse circuits that I could see.

 

With the stereo/CD changer apart, I could see that a homemade CD with a sticker label had lifted up and gotten all snagged in the mechanism. I was able to slide the CDs back into their center position near the spindle. Then, I plugged the white harness connector back into the car, and held the eject button until "Eject All" appeared on the display. As it shuffled the CDs out, I helped it along by pulling them gently as they popped out.  

 

After I put it all back together (minus the nemesis sticker CD), the CD changer worked again and current draw with the car off was back where it should be.

Those Cd changers go bad all the time and will likely cause a problem again even though you have no CDs in it. Best to put in an aftermarket head unit before it kills your new battery.