condenser fan constantly running

hi all,
I found this while surfing and looks awesome to me and give me hope on this. I bought this fridge (LG - LFX23965ST) in Nov 2010 with sears warranty. I have food getting frozen in fridge and i noticed fan in the back (not compressor) keep running all the time.Only time it stops that I open the fridge door. I asked technician about it and he did not answer me. So I don’t know whats going on. My question is

Should the condenser fan keeps running all the time? And when I open fridge door should it stop?
Thank you all in advance