Today I was driving it intown for a few hours and everything was find (it was about 85) until I turned on the a/c, then my tempreture gauge started moving up to 110c, so I turned the a/c off and the temp started going down....

Later, I found that the auxlilary fan (in front of the radiator) does not come on at all, please help me troubleshoot that or let me know if I need to open another thread.?

I drained the cooling system and refilled it, water pump appears to work perfectly.