If the AC is on, this is normal.
Low on coolant or your sensor needs attention.
The relay is sticking. Replace it.
Simply bypass the cooling fan thermostat .G
check the cooling fan sensor somewhere attached of the fan housing.
If it runs even with the car shut off it is probably a bad switch. If it runs all the time with the engine running it is probably a bad temp sensor.
The 1991 Toyota Corolla cooling fan will stay on all the time if the temperature sensor is malfunctioning. Replace the temperature sensor.
bad temperature sensor
No.
your cooling fan(s) is/are not working your cooling fan(s) is/are not working
No
Most likely the temp sensor is bad