question regarding erratic temp needle

[stevearino54 at hotmail.com (Steve Lewis)]

my temp gage started sitting just above resting position on the highway. i 
have changed the thermostat and i get the same result. waterpump is flowing 
heat sems good just an f*&^ed up gauge reading. my oil temp is ok so i 
haven't any idea what it is other than possibly a temp sensor.
any in put appreciated.

steve
ps 85 1.8 8v