How do you Verifypositive and negative wires with a multimeter?

To verify positive and negative wires with a multimeter, set the multimeter to the DC voltage setting. Connect the black probe to the negative terminal (common), and the red probe to the wire you want to test. If the multimeter displays a positive voltage, the wire is positive; if it shows a negative voltage, the wire is negative. If the reading is zero or close to it, the wire may not be energized.