if its not blowing at all, hot or cold air, one or the other are bad. fan or the resistor.

take the glove box off, you should see the fan, check to see if anything has fallen into the squirrel cage and is jamming it. ( maybe something flew into it during the crash) see if you can turn it also, see if is smooth spinning by hand.

you can also check for power at the resistor and the fan.