Well I had an email conversation with Dan at KH (great service on a Sunday). His advice was check the earths, did that zip.
Meanwhile I called out the AA who arrived in 25 mins (the last time we used Morgan rescue took 4 hrs). Thank you Admiral ins.

It was the battery. He reckons one cell is faulty. The car is 2 1/2 years old but for 1 year it sat at Central Morgan who said they put cars onto charge nightly.
The alternator is pushing out 14.4V but the battery 10.2V. It never occured to me it could be the battery. These AGM ones just die in my experience.

He said it is not uncommon for AGM batteries to fail so quickly.
So the OS light really meant not enough volts.

A new battery is enroute.


JohnV6
2022 CX Plus Four
2025 MG ZS EV aka Trigger