I have a 2010 allroad. I've owned the car since 2020 and shortly after buying it the crank pulley failed onme and after having that repaired I noticed the parking sensors stopped working closely followed by the rear wiper. I didn't let these issues bother me as I barely use the car as I use a van most of the time.
More recently I got the message "alternator fault battery not charging" so I had the alternator reconditioned and refitted however I'm still getting this fault intermittently. Totally random it will be working or not. If it does work it will continue to work the entire time until I switch the engine off. It can be working 5 times in a row then next time I start it I get the fault.
When the fault comes on I have tested at thetions alternator with a multimeter and it's putting nothing out. When it's working it's putting out over 14volts without fluctuations.

I have noticed if I disconnect negative battery terminal then reconnect before I start then it works every time.

I am wondering if the rear wiper motor being faulty may be causing it or if my reconditioned alternator is not with genuine parts and the can bus is not happy communicating with it?

I'm stumped with it now, does anyone have any advice? It would be much appreciated.

Cheers
Gary