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 only valid with the engine running