Purchased today, it ran great for about 35 mins for me to drive it home. Ran some errands, had to re position it in the driveway and all was well. About two hours later, my son used the keyfob to unlock it and that was it. Horn won’t even honk. Battery was showing 12.5v. I do have it hooked up to a charger but it seems like power just isn’t making it anywhere. 3 faint symbols on the dash when the key is in accessory.
purchased today since we needed another car and I’m head in hands over here.
2002 S40, 121,000 miles and no mechanical issue per the 78 year old man who I purchased it from. Alternator and battery are almost one year old.

 

I'm not intimately familiar with that model (at all) but when power's not getting where it needs to go, the trick is to start where it IS (the battery) and start tracing forward. When you find good voltage on one end of a cable / connector and not the other, you know where the problem is.

Also check the ground straps to the engine block and body - when those fail, it can do some odd things. You shouldn't be able to measure more than a small fraction of a volt from the battery negative terminal to the engine block or body.

And of course, the most common failure point is loose battery clamps (you can measure from the battery post to the clamp - should be zero volts - if it isn't, tighten 'em up).

 

It’s strange. Like right now, my son went out there to show his friend, and it’s cycling the CD feeder. But not able to use power locks.

 

as noted start with checking voltage on the far ends of the cables - then move up to the relay box. also try jiggling the key - its possible you can get voltage to the accessories like the radio which don't require the key to be in position 2.