Check your fan switch
http://www.peachparts.com/shopforum/showthread.php?threadid=45680&highlight=fan+switch
bear in mind it cuts in a little over 100, like 105. You can test the rest of the system by faking a fan switch cut in.
To do so, locate fan switch (see link) and pull the plug off the top. Then, short the two wires in the plug (female). It should start up. This is a very simple way to see if the fan is actually working.
Done with engine running, obviously.
Russ