Q: My coolant fan don't work why when it's in good condition

The fan is operated by a thermostatic switch and a relay or control unit, so there are several components in the chain that could fail. Diagnosing a fan that isn’t working is a matter of doing a point to point check of the fan control circuit. That said, you asked about the radiator. One simple test for a radiator is to turn on the car’s heater when the engine is overheating. The heater is like a little radiator so when you turn it on, if the engine temperature drops, it could be that the radiator’s efficiency has fallen off. The final check is to scan the radiator with a non-contact thermometer to monitor the temperature difference. It takes a bit of experience to be able to interpret the results. If you contact Your Mechanic, they can send a technician to your home or office to check out your overheating problem and let you know what is the solution.