Turn off power to the circuit
Set the multimeter to continuity mode
Insert the black probe into COM
Insert the red probe into V/Ω
Touch the probe tips together to verify the meter works
Place the probes on the two points you want to test
Listen for a beep or watch for a near-zero resistance reading
If there is no beep or the reading stays high, the circuit is open
If testing a component, disconnect it from the circuit first if possible
Avoid touching bare probe tips while measuring
Restore power only after removing the meter from the circuit