[Jut]

So long story short, I took a stupid chance buying the car (on the dealer's assertion that their mechanic had tested the battery and alternator, both were fine, and the dash warnings were simply not clearing but nothing to be worried about). In retrospect, massively stupid risk to take and was obviously going to come back to bite me.

Car did indeed drive for about 2 weeks of light use before the battery died. A local garage I trust and have used for years have fitted a new battery, and attempted to replace the alternator with both the 140a and 160a versions to be sure it's not a case of the wrong one being on the car - none of this has resolved the Power System Service Urgent warning or the red light on the dash. They are confident the car has an electrical problem requiring expertise they don't have, and suggested if I can't get the dealer to take it back, to take it to an auto-electrician to get to the bottom of it.

I am liaising with the garage I got it from about them taking the car back to sort out the issues but they are being predictably resistant so far.

Assuming that it is not the alt or the battery, is the CEM the next most likely culprit? I don't have a VIDA but I do have an ICarSoft Volvo scanner, which was reporting a fault along the lines of no LIN signal from the alternator to the CEM. The current alternator is a Bosch Volvo unit, part number 30667894.

Any help gratefully received, as I don't have faith that the dealer's mechanic knows what they are doing, even if they are willing to take the car back in for repair. Shame, as it is otherwise in pretty good order. Also, not like there is a glut of decent late P2 S80s left to choose from if I did decide to chuck in the towel on this one.

FWIW the dealer reduced the price of the car to allow for me to buy a replacement stereo for it, which I have done and have fitted, so if I handed the car back to them now, I'm out of pocket for that as well unless I refit the HU850 to it. What a ballache.