Electric fan and temp guage

[glpnet]

Just baught a 1993 Cherokee Sport and the temp guage doesnt move , only when you crank the engine it goes all the way over and no matter how long it runs it never moves from cold. The electric fan comes on no matter how cold it is and stays on as long as the engine is running.
Is that a problem with the sending unit or fan controller?
4.0 auto
Thanks for any info in advance.

[xjkevin]

sounds like both, but id start with the temp sending unit its easy..

[glpnet]

Electric fan and temp guage

Thats what I was afraid of.
Thanks