When testing to see whether a light fixture wire has gone bad, you should be careful (as at any time you work around electricity). Below you will find the steps you need to take to complete this test.
Step 1 - Disconnect the Power
For your safety, you will want to disconnect the power supply to the project area before you continue with the next steps.
Step 2 - Remove the Fixture Housing
In order to access the light fixture wire you need to test, you will need to remove the housing for the light fixture. Your light fixture will typically attach to your wall or ceiling with screws, which you will need to remove and set aside for later reassembly.
Step 3 - Test Resistance
Once you have removed the light fixture and exposed the ends of each wire, you will need to test them with your multimeter to see if there is resistance. Place the leads for the multimeter on the positive and negative light fixture wires. If the multimeter displays a reading, the wires should be fine. If the reading is zero, your wiring contains a short.