The common problem lies with failure of the resistor pack burning out, when this happens you have no blower except on position 4, as you have nothing this is not your problem, of course it could have gone all together.

Obviously first check the fuse which can be found in the engine fuse box, if this is ok then check the terminals for +12V (Only one will have power) with the ignition switched on.

If you do then the problem most likely will be the motor or something in between, so I would check if the motor itself works by putting power directly to it.

The A/C light works so by that I would think the switch itself is ok, otherwise the A/C light would not illuminate.

Martin