V200 Electrical System Circuit Tester Functions: 1. Power injection, measuring, ground testing, polarity checking, continuity testing and component activation. 2. Read the AVO meter, voltage, current, and resistance. 3. Energize the electrical components, such as the cooling fan, relay etc. 4. Activate the components 5. Determine the positive, negative and open circuit. 6. Test the bad ground contacts, follow and locate short circuits without wasting the fuse. 7. Test the continuity of the power switch, relay and diode. 8. Protect the tool from overload. 9. Allow you to work in the dark area by using the built-in head light. 10. Test along the vehicle by the long cable.