95 legacy wagon help needed!

Today my ABS light came on while I was driving. I got home and turned the car off, and there was a strange humming-like noise coming from under the hood, on the passenger side. Almost sounded like a fan, but louder. When I went to start my car later on, the battery was completely drained, and I needed a jump. Are these two events (ABS and humming) related? Anyone know what the cause of this? Is this a common problem? Approximate cost to fix? I dropped it at the dealership's night drop, but would appreciate any feedback you can provide, so I'm not shocked on Monday morning. Thanks in advance!

Could be something as simple as a broken fan belt. I noticed you said or ,I assumed, you drove the car after you had it jumped and didn't notice anything else, rough running or over heating engine etc.

no, no difference in how it ran after it was jumped. would a broken fanbelt keep going even after the car has been turned off?

I had the exact same problem, I have a '95 legacy. The problem is your ABS hydraulic motor, they actually fail quite often on Legacies. The motor malfunctions and basically just keeps running, that's the humming that you're hearing, and that's why your battery is drained. You'll need to replace the hydraulic motor eventually if you want ABS (it seems to happen to me more often in cold weather). A temporary fix (the way that I worked around it) is to disconnect the power cable that is connected to the hydraulic motor itself; just yanking the fuse out of the fuse box doesn't work, I tried. If you pop the hood, look on the left front side of the engine, right in the corner is the hydraulic motor. If you disconnect the power cable connected to that motor, you'll lose ABS, but it will at least stop running and draining your battery.

Just an add on:

http://auto.consumerguide.com/Auto/Used/reviews/full/index.cfm/id/2104/act/usedcarreviewreliability/

Look under "brake noise"