No air flow from AC vents [video included]

Please help. I'm trying to get the heater working (dont even care about cold air).

When I turn the knobs I just hear a repeating buzzing sound. I've pretty much opened up/cleaned the entire system, but I'm newb to diagnosing anything.

Here's a video of the buzzing sound. https://youtu.be/_i4TemV_g_A

No air flow from AC vents [video included]