I have an 03 S60 2.4T that has been a problem through and through. Last winter I ran into some trouble where I was having to jumpstart my car everytime I wanted to start it unless i unplugged the battery. I had everything checked (starter, alternator, battery) and everything checked out fine. I eventually heard my alarm going off late at night, so I had that replaced. Problem didn't go away. So I put a new battery in and the problem diminished, but still if I leave my car somewhere a couple of nights, it will be dead when I get back. The mechanic who worked on it (a Volvo specialist) told me he checked for a draw, and while having removed every individual fuse, a draw was still apparent. So I am really curious as to what is draining my battery. Also, probably unrelated, I am noticing a winding noise whenever I accelerate in my car. Is that normal?

 

I can't help you on your battery drain issue. But the winding noise sounds like the noise a the turbo unit makes at times.........normal. I had some noise on a recently purchased 2004 S60 2.4L (Non-turbo) that sounded like slight metal on metal, especially when first running engine. Had it checked out by an independent Volvo shop and it was both the power steering pump and the alternator: Estimate $700 alternator and $600 pump parts & labor. I decided to exercise my mechanical skills and I installed new ones myself with parts bought at my local Advance Auto Parts store for $500 after cores returns. Saved $800 from the Volvo shop doing the work. Also, Advance Auto says they provide life-time warranty on these parts so if one fails, just bring it in with receipt and they will furnish a replacement one FREE.......best warranty offer I've ever received from any repair shop!

 

I had this problem with our 850. We've had 3 new batteries replaced in 5 years by the dealer since we bought the car in '99. Eventually tired of this b.s. of jump starting the car (always in the winter time at that) the dealer mechanics got checking the whole car and found nothing except as a last resort ended up replacing the heavy wire running from the battery to the starter motor. I didn't like hacking the harness and was sceptical of the fix at first but we have not had any problems since.
Now how you would go about doing this on an S60 with the battery in the trunk? Humm ...