Toyota Repair: Corolla Overheating, radiator fan motor, 1991 toyota corolla

Question
Hello Ted, I have a 1991 Toyota Corolla that was/is overheating. I changed the thermostat, replaced the coolant and also replaced the radiator fan relay because the radiator fan was not turning on. The car now still overheats but it takes longer. My neighbor and I tried to figure out what is wrong with the car. The radiator fan motor works because he jumped it from the batter to the 30amp fuse on the fuse box. All fuses in are working since we tested every single one. Could this be an electrical wiring problem? Or is there a sensor that needs to be replaced that is in the thermostat housing? Please help since I have been trying to fix this for over 2 weeks now. Thanks!

Answer
Does the cooling fan come on when the engine gets to operating temperature?
If not, disconnect the connector on the temp sensor on the thermostat housing, the fan should run all the time with this disconnected as long as the key is on, if this is the case replace the temperature sensor. With the fan running all the time the engine should stop overheating, if it still overheats there may be a restriction in the radiator, some of the core may be clogged causing a reduction in coolant circulation, it may be necessary to replace the radiator or at least have a radiator shop check it, they may be able to clean it out.