don't know what to make of it.

[harleycat]

i have for a while now had a knocking sound (from heat/ac unit) everytime i start my car and turn on the heat/ac. it will knock for about 10 secs then stops. the heat and ac works perfect. does anyone know what this may be and how to fix it?

[anthony]

check the tiny motor forget the name of it it , if you look where your left foot would be in the middle console
and up youll see a motor with an arm on it for the heating it diverts air to the top vents or defrost etc ,it might need replacing