Furnace sail switch tripping

A furnace that tries to start, you hear the igniter click, but it shuts down before staying lit — that's often the sail switch (airflow safety switch) not seeing enough air movement. Check the intake and exhaust vents outside for blockage (bird nests and debris are common), and check the blower wheel isn't caked with dust reducing airflow. A sail switch that's just weak/worn can also cause this even with clear vents. Which furnace brand, and does it click and try repeatedly or just shut down once?