The cooling fan on the 02 saturn sc1 is not working and the vehicle is overheating. I changed out the fuse and relay and no luck. I noticed the wires the plug into the fan had been laying on the exhast manifold and the rubber was mellted down to bare wire But the wire look intact. Could this be my problem or the thermostat or the fan motor itself. How do I determine which is the problem and how do I fix it

Have the vehicle checked for DTC'S - diagnostic trouble code's if you haven't already . The vehicle has two cooling fans an three control relay's that are energized by the PCM - engine computer . Coolant temp sensor tell's the PCM engine temp.
Do you know what a wiring diagram is ? Free one's here http://www.bbbind.com/free-tsb Enter vehicle info. year make , model an engine . Under system click on engine ,then under subsystem click on cooling fans . Click the search button then the blue link. Watch this video.
Relay Driven Dual Cooling Fan Diagnostics

Also ,what are you going by to say it's overheating ? Temp gauge in the instrument cluster ? GM had problems with Stepper motors inside the instrument cluster . 2003 - 2006 . Hooking up a scan tool that can view data would show what the coolant temp sensor is tell the PCM .

Using a infered temp
This would show the real temp of the engine.

DTC P0480 or P0481
Battery positive voltage is supplied to the cooling fan 1 relay from the COOL FAN #1 fuse. The powertrain control module (PCM) controls the cooling fan 1 relay by grounding the low speed cooling fan relay control circuit via an internal solid state device called a driver.
Battery positive voltage is supplied to the cooling fan 2 relay and the cooling fan 3 relay from the COOL FAN #2 fuse. The PCM controls the relays by grounding the high speed cooling fan relay control circuit.
When the PCM is commanding a relay on, the voltage potential of the control circuit should be low, near 0 volts. When the PCM is commanding the control circuit to a relay, the voltage potential of the circuit should be high, near battery voltage. If the fault detection circuit senses a voltage other than what is expected, the DTC will set.
The PCM will monitor the control circuit for the following conditions:
• A short to ground
• A short to voltage
• An open circuit
• An open relay coil
• An internally shorted or excessively low resistance relay coil
When the PCM detects any of the above conditions, the DTC will set and the affected driver will be disabled.

I would say the instrument cluster is probably the problem . If the fans come on when A/C is turned on the system is working.

How to repair GM Instrument Cluster Speedometer Gauge Stepper

How hot is it getting in degrees F? Some electric fans won't even turn on, till around 220 degrees F. Does the fan turn on at all?
As far as overheating, does the coolant recovery reservoir fill up in a hurry?
Sometimes after opening up the cooling system, you get air in the system that may cause temp gage to react.
What about your thermostat? Did you check for coolant flow through the radiator? Another thought might be a head gasket issue, I'd check everything else first.

If the fan not turning on when car engine getting hot,then car will notice overheating.Click this link below for troubleshooting:---http://technoanswers.blogspot.in/2012/02/car-running-hot.html--------To know how engine cooling system works ,click the link below :----Engine cooling components working?

http://repairhelpcenter.blogspot.com/2011/11/engine-cooling-components-working.html

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How does Vehicles Engine cooling system works? http://repairhelpcenter.blogspot.com/2011/11/how-does-vehicles-engine-cooling-system.html
------------How to Replace Engine cooling Fan:-- http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-engine-cooling-fan-on.html
-----------Replace Fan Relay but still Radiator cooling fans not working? http://schematicsdiagram.blogspot.com/2011/12/replace-fan-relay-but-still-radiator.html
----------DIC says "COOLING FAN FAULT"? http://schematicsdiagram.blogspot.com/2011/12/dic-says-cooling-fan-fault.html
---------Where Is Radiator Fan relay and Fuse Located?

http://schematicsdiagram.blogspot.com/2011/12/where-is-radiator-fan-relay-and-fuse.html

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This will help.

Thanks.

A bad relay will not blow a fuse. The radiator cooling fan must run with the A/C on or the vehicle will overheat and the A/C will perform poorly. First I would check the draw on you cooling fan motor-it may be blowing the fuse, or you have a wire shorted to ground.

car over heats at idle when i turn on ac it cools down. checked relay fine,fuse is fine.help!

Does the car overheat at idle? If yes, first check fuse in fusebox in engine compartment. If fuse good, check for voltage at fan connector using test light with engine on and car hot. If no voltage, replace fan relay in engine compartment fusebox. If voltage is present, replace fan. Please reply with any additional questions.

Sounds like a case of a bad radiator elec. cooling fan motor, fan should come on with a/c on, if it don't, check fuses, if fuse ok, check for voltage at cooling fan motor, if you do have voltage, replace elec. cooling fan motor.

If your cooling fan is not working you solved your own problem. The cooling fan is what helps your radiator perform its function. The radiator cools down the antifreeze mixture by separating it into small tubes separated by air fins, the fins allow a greater surface area for air. The radiators main function is to dissipate heat into the surrounding atmosphere which it can do well at highway speeds without a fan, but most modern cars need a cooling fan to help pull air across the radiator.
The wiring diagram for your vehicle suggests that there is a 5 amp fuse 4 and a 40 amp fuse 42 that run the radiator fan and control which should be located in an under hood fuse/relay box. Check them with a test light on both sides, with the light to ground you should see a positive voltage at both sides. the 40 amp would most likely be a maxi fuse, or a larger size then the regular atm fuse for the 5 amp,

try the relays the car is old high miles relays are like light bulbs burn out all at once

Two things to check. The fan relay, and the coolant temperature sensor. There may be two sensors, the two wire one is for the computer hence for the ran relay. Buy a haines manual at your local auto parts store. This will help you find what you are looking for, and its only about 15 bucks.

Alternatively you can put a jumper accrss the fan relay to make the fan run whenever the engine is running.