How To Know If The Alternator Is Charging. If any of the voltages are below spec its a strong case for a new alternator. If voltage is good turn on the headlights interior lights radio heater and any other electrical load.
All cars with an internal combustion engine minus a few select hybrides have an alternator. Connect a multimeter or voltage meter to test the alternator. I had a Denso remanufactured alt.
The alternator is charging if the battery voltage stays above 13 volts with the engine at 2000 rpm and all accessories on.
Without the alternator the battery will eventually discharge. I had a Denso remanufactured alt. While your car is running disconnect the positive battery cable. It should be more like 128.
