1990 corolla temp gauge

I just replaced the motor in a 1990 corolla with the 4afe engine. The
previous owner had driven the old motor after the water pump blew, and
needless to say cooked the motor. I have replaced it witha used one
out of a junk yard, and it runs great except I can't get the temp gauge
in the cab to move. It seems as if the coolant is flowing properly,
the radiator has good pressure, and the heat out of the vents is great.
I replaced the water pump when I installed the motor. I looked at the
repair book, and it's calling for a temp sender in the motor (which I
can't find, probably due to the fact that the book covers 10 years of
the corollas) and a fan switch near the coolant intake for the motor.
Any suggestions?