Electric fan does not come on for radiator. Everything checks out, is there a way I can jump the fan to see if it is operational at all.

If you make a jumper wire and jump the load side of the relay and the fans work, it might be the relay or it might be the control side of the relay not getting the signal from the temperature switch. If you jump the load side and the fans don't work it's either the fan motors or a wiring issue between the relay and the fans.

experience has proved that flushing a radiator is a waste of effort
the flush only cleans out the open tubes and not the blocked ones and the salts in the block now flow into the radiator and block the rest
check the fan operation
viscous fan hub --replace the fan hub
electric fans check the system from the coolant sensor , fuses (2) , relay and fans

Check some of the simple things like coolant level and leaks under the car or under the hood. Then have your car running and observe the front Electric fan by your radiator.

When the engine starts to get hot, this Electric fan should turn on. You may also be able to have the fan turn on when you set your A/C to work. Different makers prioritize different controls and some offer a 2 speed fan design to help when things are really hot.

The Electric fan is suppose to be turned on by a temperature sensor. The sensor will activate a Relay which provides power to the Electric radiator fan. You can obtain a wiring diagram and a fusebox layout drawing by going to Autozone.com and registering your vehicle for free.

Once you have these diagrams you will know what size fuse the Electric fan uses and where it is in the Fusebox. You can take off the radiator Electric fan for testing or just jump some power to it to find out if it is bad.

For the rest of the controls like the Relay, you can use a Voltmeter to trace where the power stops, then fix that part. Remember that for testing the Relay, the Ignition should be on.

The next reason for overheating is a stuck thermostat in the water system. You would need to follow the big hose coming off the top of the radiator and running to the engine. The thermostat should be contained in this housing.

Finally, it is not impossible for the Radiator to go bad and clog up. But manufacturers using aluminum engine parts often have trouble free aluminum radiators.

I had a 1987 oldmobile that had that problem. It turned out that the fan clutch thermostat had gone bad and would not engage when the engine heated up. The fan clutch was part of the fan. I replaced it and solved the problem.

Turbo Radiator Fan

The radiator cooling fan is a variable speed electric motor driven fan. The radiator fan assembly includes an electric motor, fan blade, and a support shroud that is attached to the radiator. The radiator fan is serviced as an assembly (fan motor/fan/shroud).

The variable speed radiator fan is controlled by the Powertrain Control Module (PCM) by way of a Pulse Width Modulated (PWM) signal. The duty cycle ranges from 30% for low speed operation then ramps-up to 100% for high-speed operation. This fan control system provides infinitely variable fan speeds, allowing for improved fan noise, A/C performance, better engine cooling, and additional vehicle power.

To control radiator fan operation, the PCM looks at inputs from:

Engine coolant temperature
A/C pressure transducer
Ambient temperature
Vehicle speed
Transmission oil temperature (automatic transmission only

HENCE CHECK THE PCM

For many of the 90's and 2000's Toyota various models - Camry, Tacoma, 4 Runners, Corolla, and some other models overheating is usually caused by temperature sensitive fan switch on the radiator not operating. Electric fan on the radiator should operate when temp above 200 degrees. Less often the control relay 90987-03003 is defective. Check if bubbling in the radiator smells like exhaust. That would indicate a blown head gasket. A jumper wire from your marker light positive to the lower contact in the fan control relay socket will operate your fan when parking lights are on. The larger vehicles with more powerful radiator fans will need a hefty jumper from a headlight positive to avoid overheating the lighting wiring. Make sure the engine is off and warmed up to check the radiator core with your hand to see if it is getting circulation. If it is all cold the thermostat might be stuck.

Thermostat

Test thermostat in a jug and pour boiling water on it , it should compress meaning it works. Check that the waterpunp is operating pushing water into the engine .Check that radiator water flows to the watrpump. Is tension of fanbelt of waterpump sufficient that it doenst slip. Lastly check that the radiator fan is working if has a electric fan. if this doesn’t help check if radiator or engine water passages isn’t blocked.

Make sure the electric fan if equipped is coming on after 10 - 15 min. of operation if not replace the fan relay. Make sure antifreeze/water is a 50/50 mixture, If the fan relay doesn't do it replace the fan if the car has no electric fan the clutch fan may be faulty if equipped.

1. you're paying for their experience and knowledge.
2. you can fix it yourself if you research electrical circuits go buy a muti meter and spend some time.

if the fan has power to it when the engine is at operating temp. the fan is dead. if it doesn't have power check the fuse or relay that sends power to it. it that's ok check the thermostate switch that tell the fan to operate (jump the switch the fan should come on.

now whose going to pay me? lol :)

the aux fan only works when the ac is on, and has come to a predetermined temp(?) i found this out while going up a long grade in the back country without the ac on and later found out the radiator was half plugged!