- 1). Test the battery voltage by attaching the leads from the digital volt/ohm meter to the battery terminals. The minimum battery voltage for proper operation of the electrical system is 12.5 volts, with the ignition switch in the off position. If the battery voltage is below this, charge the battery before further testing to eliminate faulty results.
- 2). Test for battery voltage at the large power wire on the back of the alternator. Battery voltage must be present here to turn the field coils on in the alternator. If voltage is not present, check fuses and wiring for open circuits.
- 3). Start the engine and test voltage at the battery with the engine running. It should be 13.5 volts to 14 volts if the alternator is functioning properly. Turn the headlights onto high beam, and the heater blower speed to high. The voltage should be stable, or rise slightly, to meet the added demand of the electrical accessories.
Subscribe to our newsletter
Sign up here to get the latest news, updates and special offers delivered directly to your inbox.
You can unsubscribe at any time