Originally Posted by PAhonda

Think on open/closed as connected/disconnected. You can use your volt meter to test this using two settings. Resistance or open/closed setting.

1. Resistance is a setting on every multimeter. Resistance is how well a metal conducts electricity. Copper has very low resistance, as does aluminum and iron metal. If your resistance between two wire ends is close to zero ohms, then those two wires are closed. If the resistance is infinity (same reading you get on the volt meter when the wires do not touch each other), then those two wire are open.

2. There is a diode or open/closed test on some volt meters where the meter will beep when the circuit is closed, or not beep when the circuit is open. The meter is basically doing the same test as resistance, it is just beeping when the circuit can conduct any electricity.

A diode is an electrical component that conduct electricity in only one direction. Imagine that a diode is in the middle of the wire and will conduct electricity from left to right. If you touch the + volt meter lead on the left and the - volt meter lead on the right, the wire would test as closed. If you switched the volt meter leads, then the wire would read open.

You can use either resistance or open/closed setting on the volt meter to do these tests.