Hello again everyone!
Ok so 2 days ago, I drove to school for another exciting day of philosophy 101.
And when I came back to the car, you guessed it, dead battery.
Long story short, called AAA, battery only holding 29 CCA instead of the rated 550 CCA, blah blah bought a new one, replaced it, works fine.

Before i go off about the problem, i should probably tell you what car i have
2002 S40 1.9T

Now since i had to disconnect the old battery, I ran into a bunch of problems, most of which i have figured out

The first one that struck me was the airbag light would not go off, researched it, turns out its common when you replace the battery, the light turns on due to low voltage... yadda yadda whatever.
The second issue is with the stereo system, requires the anti-theft code which i dont have (not the original owner, i think im third, so i have no clue where that card is... )

These are all little problems, but one problem has my serious attention. A constant whirring sound, almost like the window washing fluid pump that stays on very close to the fuse box... I have checked the relays, It does not seem to be any of them... The sound is there always, it goes away when the car is off, and it does not change with RPMs, its a constant, non changing whirring/buzzing.

I have a feeling I have heard the sound before, but it would always go away a second or two after the car was turned on, now its on, constantly. No behavioral changes have been noticed, everything normal.. except for that airbag light.. This sound started after I tried to jump start the car, this is also when the airbag light came on, the two things happened simultaneously, during a jump start.

Now about the precise location of the sound, I have been unable to pinpoint exactly where the sound is originating from, but right next to the fusebox there is a little blue/black thing that has a cable running through it, it looks like its coming from the cabin, going to the right front of the engine... If i didnt know any better i would say this is the mechanical connection of the accelerator... but please dont take my word for it, i have no clue what this thing is. The only reason why i think this may be the source is because it vibrates at the same frequency as that sound that im talking about, but when i touch the other parts in that surrounding area, everything else is either not moving at all, or moving with the jolt of the engine

If you have any ideas of what this may be, please let me know and thank you!


ATTENTION!
So i just went out there and checked again for that sound, I HAVE heard it before. If i turn the key to the "ON" position, without actually starting the car, that sound comes on for a few seconds (as i said earlier) and then goes away. But when i take the key all the way and start the engine, the sound comes right back on and stays. After trying to figure out where the sound is actually coming from, i noticed that there is yet another blue thing next to the brake fluid reservoir. The one I was originally talking about is just in front of the reservoir, then there is one thats to the left of the reservoir, and a few inches lower, I presume its some form of valve or pump as it has 2 hoses coming from it, its completely possible that there are more hoses and electrical connections, but i just didnt see them, this thing was not very easy to see from the drivers side of the car. And just as a note, the original plastic thing i was talking about, with the cable running through it, that piece also has a 2 wire electrical connection to it, I'm assuming its a position sensor of sorts... again no idea


Thanks again fellas, appreciate your help!