Hello, all. I have a 2012 XJ s/c 5.0 that a few days ago started a snow issue. Starts and drives fine. A few days ago I got a message on my radar detector that I had low car voltage. I connected through Torgue, and it agreed with the low voltage. Again, it starts and drives fine, but shows 12.1V. I charged the battery (a 3 year old AGM) , and the voltage after charging was 14 V. Driving the car immediately afterwards the voltage continued to register 14+ volts, until I shut it down, and started it again after a few hours, when it registered 12.1V again. Looking through the posts on similar charging issues, I have seen a fusible link could cause this sort of thing. Without the complications of electronics. I normally would gravitate toward a bad alternator, but now I am not sure. Any thoughts are appreciated.

 

Doesn't sound like an alternator issue, since the car managed 14V while running. All of the big-box auto parts stores will check your battery and charging system free of charge. Start from there. If that checks OK, I'd look for a parasitic draw that is occurring with the engine Off.