I shut my 2007 s40 off and the key wouldn't turn all the way to the off position but everything was off. I went to try and turn it back on and everything was still dead. No interior lights and nothing happened. Prior to this on my way home the headlights along with all interior lights would pulsate (go dim and bright really quick for a few minutes) and right before I shut it off the radio was cutting out. I'm not sure where to begin with this issue. Thanks for any help

 

Try unlocking and rowing the shifter and realign the steering wheel. Its possible the PNP switch thinks you are in gear or your steering wheel lock is pressing. Otherwise, jiggle the key and consider a new switch.