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Measure the voltage at the 12V accessory socket. If the alternator is running it'll be somewhere in the 13.5 - 14V range. If it's just the battery, it'll be m
by caf 6y ago
Measure the voltage at the 12V accessory socket. If the alternator is running it'll be somewhere in the 13.5 - 14V range. If it's just the battery, it'll be more like 12-12.5V.
- chrissnell 6y agoI'm pretty sure that you can read this off the OBD-II port, too. Plenty of cheap readers that will work with your smart phone are available online.
- throwaway0a5e 6y agoThere's a 12v pin in the OBD2 socket to power whatever OBD2 reader or Bluetooth dongle you have plugged into it so you can use that to read the system voltage for the vehicle.
- ilyagr 6y agoThanks, this sounds pretty easy. For my and others' future reference, here's a random video of how to do this with an obd2 port, as suggested by a child comment: https://youtu.be/dDY2lMMrpLU https://youtu.be/dDY2lMMrpLU This may or may not be more convenient than the accessory socket.