My radiator fan doesn't come on, i replaced the fan switch on the fan and the temperature sender, my heat gauge is working and both the water hoses are equally warm. Vehicle Opel Corsa 2000 ,bakkie.

I need year--make--model to look up wiring info?

No rad fine check the fan is working ,either the fan motor ?? connection to the fan motor ?? fuse ?? relay?? or temperature sensor?? any one of these will cause the fault

probably a faulty temperature sender unit
temp sensor unit which controls the fan)

What's chances that the temperature gauge or sender itself is wrong?
Is the heat exceptionally hot? What temperature is the heater dicharge when the gauge reads 260?
I think that the sender is not expensive, try that. An auto parts store could get you an inexpensive dial gauge that you might be able to install in place of the sender.
Gary

The temperature you see on the dash board gauge is not necessarily the actual temperature of the coolant. The engine has a 'coolant sensor' which sends information to the electronic control unit (ECU /PCM) and there is a separate 'sender' which governs the gauge reading you see on the dash board. The sender usually has just one wire connected to the top of it. The sender is basically a heat dependent resistor and the temperature gauge simply reads this resistance. Sometimes corrosion in the electrical connector can inhibit the correct readings, so first disconnect the sender and inspect/clean the pin with a little wire wool. Now check the coolant. First put the interior heater on maximum heat. Run the engine up to working temperature and then squeeze all rubber hoses to help shift any trapped air. Top up the coolant if the level drops when air pockets have been shifted. The following sequence should occur when the engine is warming up. 1) When cold the engine has higher then normal revs. This is due to the coolant sensor (not sender) telling the ECU that the engine is cold and that the injectors should add more fuel to compensate for the cold condition of the engine. 2) Within about a minute the idle revs begin to drop as the coolant sensor detects the engine warming up 3) After about 5 minutes the thermostat should open. You can detect yourself this by feeling the top rubber radiator hose getting hot. 4) If you have an electric cooling fan on the radiator this should switch on about now. If you have a fan driven by a viscous clutch this will engage a little later. 5) after about 2 more minutes the face of the radiator should be becoming hot and the bottom rubber radiator return hose should become warm, then hot.
If you have an electric fan and it fails to come on then check the electric relay and fuse for it. Viscous clutch fans should always show some resistance when turned over by hand when the engine is off, if it spins freely then the clutch coupling is faulty and it will need to be replaced. A sign of faulty fan related over-heating is a car than runs at normal temperature when cruising on the freeway but overheats when standing at the lights; fan engagement is to compensate for the lack of air flow across the radiator core when the vehicle is stationary.
I hope the above helps

Hi,
Firstly check that the engine is actually over heating, you may have a faulty water temperature sender unit.
Also check your gauge is ok, disconnect the water temp sender wire and the gauge should either go to hard hot or cold. If neither happens your gauge is faulty.
Let me know how you get on.
Also check your fans are coming on to cool the radiator, if the engine is getting to over half way on the temperature gauge and the fans are not coming on then you have a faulty coolant fan sensor.
Replace this and you should be ok after that.
Thanks
Jason

The thermostat that governs the running of the radiator fans is different to the temperature sender to the display, Check out the temperature sender for proper operation and possible loose connection.

If the temp. gauge on the instrument panel is OK, test and eventually replace the temperature sender, and check the wiring to temperature sender.

Replacing the whole heater core is not a simple operation, test sender and wiring first.

have sex with it,.. it will feel better promis

Below u will find Auto zone list for reason ur car can over heat Shaun Inspect Cooling System Mix Coolant level low or flow is restricted. 2 Inspect Belt Incorrectly routed, adjusted, tensioned, missing, or worn water pump belt(s). 3 Inspect Oil Pan Gasket - Performance Ruptured, cracked or leaking radiator hose. 4 Inspect Radiator Cap Worn or damaged radiator cap 5 Inspect Thermostat Thermostat stuck closed 6 Inspect Fan Blade Broken, missing, or defective fan blade(s). 8 Inspect Water Pump Damaged, worn or leaking water pump. 9 Inspect Intake Manifold Plenum - Perform Leaking water pump gasket. 10 Inspect Cooling Fan Control Faulty cooling fan control or circuit. 11 Inspect Cooling Fan Switch - Radiator Faulty radiator cooling fan switch or circuit. 12 Inspect Engine Temperature Sensor Faulty engine temperature sensor or circuit. 13 Inspect Temperature Switch Damaged or faulty temperature switch or temperature switch circuit. 14 Inspect Fan Clutch Worn, loose or faulty fan clutch. 15 Inspect Ported Vacuum Switch Damaged, leaking, or faulty ported vacuum switch. 16 Inspect Radiator Obstructed radiator core or radiator cooling fins. 17 Inspect Head Gasket - Performance Head gasket leaking coolant into cylinders