Allows user to track electrical system voltage on any vehicle with a normal 12V charging system
When the “normal” green light is on, the system voltage is normal and the battery is being charged correctly; if the “high” red light is on, the system voltage is too high and damage to the battery may result; when the “low” red light is on, the system voltage is too low and the battery is being discharged
The above indications are valid only with the engine running