92 Buick Lesabre, more miles on it than I care to admit...

Radiator fans have decided to cut out completely. Friend suggests look for the heat sensor, but we haven't a clue where it would be. Any suggestions?

The ECT is under the throttle-body and end of intake manifold. We just rewrote the book on how the fan circuit works recently in this thread--Click Here (http://www.automotiveforums.com/vbulletin/showthread.php?t=895069)