- 1). Remove the seat to access the battery. Connect the voltmeter's red lead to the positive battery terminal and the black lead to the negative. Place the voltmeter on the 20-volt scale.
- 2). Observe the voltage on the battery. It should read 12.5 to 12.75 volts. If the reading is lower than 12 volts, you need to charge the battery before the charging system can be properly tested.
- 3). Start the engine and, at the same time, watch the voltmeter. If the voltage is 12 plus volts to start and drops below 10.5 volts when the starter activates, the battery has a bad cell and needs replacement to prevent harm to the charging system. A battery with a bad cell draws too much amperage in an effort to charge and can overheat the charging system.
- 4). Check the amount of charge with the engine running at an idle. It should display 13.2 to 13.8 volts. Turn the headlight on and observe the voltage. It should still remain in this range.
- 5). Bring the rpm up to 1,800 and observe the voltage. Voltage should appear at 14 to 14.5 volts. If it is lower, the rectifier or stator has a problem. It the voltage is higher than specified, the voltage regulator is at fault.
previous post