I have a 2000 Bonneville. The AC blower motor just suddenly stopped working. I tried giving it some fairly hard wacks with my hands but it never comes on.

I checked the voltage on the 3 pins that connect to the blower motor. With the fan on or off, one is always at 12V and the other two never have anything. It sounds like the blower isn't getting the signal to turn on. Where can I go from here? What actually gives the blower the signal turn turn on?

There should be a blower motor resistor next to the motor. I'm not sure how to check that though