Have a 2006 4.2 supercharged L322,a few days ago after starting the car the battery light came on,i revved the engine and it went off,about a half a mile later it came back,i then drove 60 miles it never came back on,started the car 2 days later and again it came back on,this time it comes on about every 200 metres,rev it, it goes off.Then 200 metres comes back ok.Have Got Code P063c Generator voltage sense,circuit low.....TIA

https://www.obd-codes.com/p063c

Sounds like the alternators kaput, or the voltage regulator is breaking down, voltage / power going up when revved is classic low load power generation prolem.

Best go to an auto electrician to have that tested, they can load test it in about 20 minutes. Fuji White / Jet 2012 4.4 TDV8 Westminster

Obrigado.........