A failed fan control switch, wiring failure, bad blower fan motor or broken blower wheel can prevent the downdraft fan from blowing.
Unplug the downdraft vent and check the motor wire harness connections. Reconnect any loose wires and repair any damaged wires.
If the wires are okay, turn on the fan control switch and check for continuity through the fan control switch using a multimeter (with the downdraft vent still unplugged). Replace the fan control switch if you don't measure continuity through the control switch.
Replace the blower fan motor if the motor doesn't run when activated.
If the motor runs but the fan doesn't move air, check the blower wheel and replace if damaged.
