'88 5ksq-cooling questions?

["Matthew S. Robinson" <msr11@psu.edu>]

What is the normal after run behavior of the radiator fan in an 88 5ksq?
Mine does not start immediately when I turn off the ignition, but waits
5-10 min. before coming on ( even if the engine is on the warm side when I
shut down).
Other (possibly) related factors:
1-I have a funky temp sender (takes _forever_ to deflect, if it does at
all, or waits until I shut down and start up again...) which I plan to
replace.
2-I have had a problem with high idle (but not since the heat wave!) where
after a drive of 30 or so mins (hwy)- the idle will not drop below
1100-1200-which causes things to get a little warm if I have just exited
the interstate and get stuck in local stop-n-go traffic. (I need to figure
this out).

Don't know if these are related...thanks for any suggestions or advice.
Matt.