2000 cavalier---2.2 standard------cooling fan not working---fan will not come on---good relay---good fan---good sensor. Air conditioner does not kick it on either---p01480 error=fan circuit

Check the wiring harness to the fan they sometimes put a fuseable link in the wire and it might of blown.

REPLACE THERMOSTAT BUT IT SOUND LIKE FAULTY COOLANT TEMPERATURE SENSOR.BUT CHECK COOLING FAN FUSE AND RELAY.IF ALL IS GOOD HOT WIRE COOLING FAN IF COOLING FAN WORKS.PROBLEM COULD BE FAULTY COOLANT TEMPERATURE SENSOR. DAMAGE FAN WIRING OR FAULTY PCM.IF COOLING FAN DONT RUN WHEN HOT WIRED.REPLACE FAN AND MOTOR.

Try changing the coolant sensor,and bleed the air out of the cooling system

CHECK COOLING FAN FUSE AND RELAY.IF BOTH GOOD SCAN CAR TO CHECK COOLANT TEMPERATURE SENSOR FAULT CODE.THE PCM AND COOLANT TEMP. SENSOR IS WHAT CAUSE FAN TO RUN AT CERTAIN TEMPERATURE.IF ALL IS GOOD.HOT WIRE COOLING FAN USING JUMPER WIRES TO BATTERY.IF FAN DONT RUN REPLACE FAN MOTOR.IF FAN RUNS YOU HAVE SHORT OR BROKE WIRE IN THE COOLING FAN ELECTRICAL CONNECTOR.

Check your temperature sending unit plug and wiring. if there is any corrosion it can cause the signal to be out of range...If it's out of range it can delay fan start up. Works like this: sender sends info to the computer, computer sends ground signal to relay, relay completes power to the fan. If the fan works on a/c, then the fan motor is good and does not need testing. A/c bypasses auto control and keeps fan on as long as compressor is running.
Also, you can have the system tested using a heat sensing "gun" Your gauge may be off a little on the high side. Unless it is actually overheating, there may not be any problem at all.
The gun test can also detect "cold spots" on the radiator which indicate a flow problem. That too can cause your symptom. Don't forget your radiator is ten years old and likely is nearing the end of it's service life. Internal blockage of core passages is common on older radiators.
As long as you have no external leaks and engine internal gaskets are good, something here has got to help!
Good luck!

since you have already tested fan and relay and both work, the problem may be the engine temp sensor. There are two sensors. One goes to instument cluster. This is engine coolant temp sensor, the other is engine temp sensor which is usually attached to engine block, sometimes they are connected to thermostat housing with the coolant sensor. You can pully the engine temp sensor and test that sensor same way as relay. (with mulitimeter)

after you check the grond in the fan conector and all the fuses i can say its coolent temp sensor.

The water temp sensor is located near the thermostat housing. This sensor is what tells the ECM to turn the fan on/off. The water temp sending unit is located near the same area. You know you have the correct sensor is because the water temp sensor has a 2 prong plug. The water temp sending unit only has 1 prong.

so hard wire a kill switch

Hi, you should start by checking your temperature suith at the cilinder head and the fan relay , those are the must comon for the problem you describe, ( be sure you chech all the fuses)GOOD LUCK......