Replaced, but not fixed yet (cruise) help

[randrews@post.cis.smu.edu (Robert Paul Andrews)]

Well guys, just had the dealer replace the cruise control switch
as it was under warranty from being replaced last July but now it is not
working?!  Bad switch again?  OR should I look for something else.  The
cruise system just won't engage all the time.  When it does, the times
I have had it on, it seems to run fine.  BTW-This is a 93 90.  And where is
the cruise system located?  TIA!
Later!
Rob
-I'd like to see if I can fix this before I let the dealer have another
crack at it. I already don't like them ;/