On my 94 SL-2 the cooling fan doesnt come on until temp gage gets really close to the red zone.One way to get around this is to turn on AC and back off and the fan will come on and continue to run until it cools down.Its as if once the relay is energized it runs 1 cycle and then goes back going dangerously close to the red zone.I usually watch it close and flip on AC if it is heating up.If this is a heat sensor for the fan-where is it? Thanks in advance

Everything you drscribe is textbook "absolutely normal" for a S-car engine. The cooling systems were a bit undersized on these cars , but not enough to cause a problem unless the fan didn't kick in.

PCM monitors the ECTS (Engine coolant temp sensor) mounted in the head in order to determine when to close the fan relay.

Original design of this sensor included resin tip which fails at an eventual rate of, oh, about 100%. So.....
______
I recommend changing your ECTS --

Use a Saturn brass-tipped replacement and also replace the connector (Saturn-only part). Even the slightest bit of corrosion may cause erroneous temp readings.

The ECTS is located in the head on the driver's side. It is a two wire device with a pinch connector. Be sure you are specific when you get the replacement so that you get the right one.
(The one-wire device is the dash gauge temp sensor (which was separate in 94)

$40/half hour

You'll be surprised how much performance you get back from this minor fix.

Again, everything you described is textbook normal for an S car engine.

Derf