Coolant temperature weirdness

[Steve Hackett]

John:

Ditto here...
    * first small mark - highway and in cold weather
    * between first small mark and first fat mark in 80+ ambient on highway
    * around first fat mark warmer weather and stop and go, fan runs normal
    * A/C on and above 38 or so ambient low speed fan is on which keeps 
gauge at first small or delays creep towards first fat when warmer out.

thermostat was installed (new) as part of a timing belt / new radiator job 
in 2003.  MFTS is about 4 years old, gauge has always been the same.

HTH,
Steve Hackett