Have you checked the cooling fan relay? ? This is the child's wooden block size relay installed in the fuse/relay box in under the hood. If it is bad the fan will not come on even if all the other sensors and components of the system are functioning. Also, This cooling fan relay draws a lot of amperage which causes it to heat up. On my '92 SC2, I have learned that the contacts of the relay have become so hot from the high current they carry that the fuse box sockets overheat and deform. It became necessary for me to open up the upper and lower halves of the fuse box and install new conductors to restore good contact with the relay pins. If you find that your cooling fan relay pins are discolored and the plastic housing is slightly deformed around the pins, you are likely haveing a similar problem. For a while I was able to just slightly twist the pins of a new relay using a pair pliers so that they would make tighter contact in the deformed sockets of the relay box. Hope this helps, JB
Cooling fan should come on when coolant temperature exceeds 235 degrees Fahrenheit or A/C or defroster are turned on
Engine coolant temperature switch/sensor
Cooling fan is designed to come on only when A/C, defrost, or engine temperature exceeds 235 degrees
The sensor is threaded into the coolant passage in the back of the cylinder head.
on the right side of the engine
Engine Coolant Temperature Sensor.
Start by replacing the Engine Coolant Temperature Sensor
Sounds like your cooling fan relay is shot. Ron J.
Refer to the link below
The guage on the dash uses the ONE wire sensor... This is located in the block near the drivers side. Eric First check to see if you have coolant in the radiator. If there is no coolant you will not get any reading from the temperature sensor. If there is coolant then change the temperature sensor.
Low coolant? Cooling fan not working? Thermostat not opening? Cooling system air bound? Water pump not circulating coolant? Plugged or restricted radiator? Defective radiator cap?
You fill the cooling system through resevour, it should have a cap that screws on and says DO NOT OPEN WHEN HOT.