Pontiac Repair: Coolant fan turns on too late..., coolant temperature sensor, coolant temp

Question
I have a 1994 Pontiac Grand AM SE 3.1 V6.  The problem is that the engine heats up (according to the gauge) into the red before the fan kicks on bringing the temp to under 220.  The fan will not come on when I leave the AC on for awhile.  I noticed you ask that often.  I live 10 minutes from work and anytime I drive that car to work it does the same thing.  I don't believe it is the gauge because if it gets too far into the red I would see some steam if it is cool outside.  I'm guessing either the coolant temperature sensor or a relay.  My Haynes manual doesn't show me where the sensor is or where any relay may be.  Any help would be greatly appreciated.

Answer
Hey Miles:
Well if the fan comes on when the a/c is running the electrical circuit for the fan works. It could be a few things. a bad temp sensor for the gauge and the engine is not really running hot but the gauge says it is.. It could be a coolant temp sensor for the computer that is reading cooler than the actaul temp of the engine thus it is getting hotter then the computer things it is before the fan turns on. It could be an issue withe engine computer where it doesn't turn the fan on at the correct temp. Usually the computer will not turn on the fan relay untill 220-225 degrees. some cars have a 2 speed fan low and hi 220 or so the low spped fan would come on and maybe 230 the hi speed fan would run.. I think that engine/car has just a 1 speed fan.... I would have the engine data scanned for the computer and see what the temp reading is compaierd to the gauge and see when it gets "hot" if the 2 reading match each other..