Jumper wires (figure 6-6) are simple, effective testing aids. They are used to complete a circuit by allowing current to “jump” across a suspected open or break. Thus, they are actually a test of continuity.
When a jumper wire is used, it replaces a suspected faulty portion of a circuit with a know conductor. If the circuit works properly when the jumper wire is in place, but not without it, an “open” is indicated in the area jumped. Use a jumper wire to bypass only nonresistive parts of a circuit, such as switches, connectors, and sections of wiring.
