Intermittent Electric Issue?
 

Hey all - just joined to see if I'm losing my mind or my car has a genuine problem.

Bought an '05 S40 T5 AWD last year and it's been great up until about a month ago. Noticed recently some weird electrical issues. A few weeks ago when I was backing into my garage, I nearly stalled the car, was able to save it, but then the car inexplicably went completely dead. Not like I stalled and could restart and keep going, the car lost all power. Left it for a few hours on a trickle charger and it's been fine and hasn't done it again.

A few days ago, it started stalling more frequently, but not to where the car loses power. It's really cold here now (sub -20C) so I don't shut the car off if I'm eating lunch on a work break or picking someone up. It seems after about 5 minutes, the car will just shut off, but it'll start back up with no problems. I'm unaware of any remote shutoff after a certain amount of time, so I'd appreciate any input on that one.

sounds like a relay or perhaps a battery cable/ battery ground cable issue. Start by cleaning the battery terminals/connectors, inspect the red main power cable for any swelling/bubbled insulation (a sign of corrosion inside the cable), check/clean the ground cable's connection to the chassis. Keep a volt meter in the car. Next time it dies do some probing of the battery voltage and various relay connections.