1992 Oldsmobile Cutlass overheating

Engine Cooling problem
1992 Oldsmobile Cutlass 6 cyl Front Wheel Drive Automatic

Two related problems. The cooling fan does not come on unless I turn on the A/C.

Second: When the temperture gauge gets to a certain temperture (right between 100 and 220) the car will not restart without cooling off. Depending on how hot it is, depends on how soon it will start. Between 1 hour to 4 hours. But the car doesn't seem to be overheated, not lose of antifreeze or bubbling. I think it must be a sensor. Now when I talk about not starting, I mean it does not crank over. Battery is new and all the electrical will work (power windows, etc.), But it won't start until "something" cools down. I know there is a Cooant Temperture Sensor. Could this be the problem. Hard to find an Olds tech now days.

Thanks in advance for your help.