Cooling fan is not working

The fan or fans that cool the engine are not turned on until the engine coolant reaches about 225-230F, so they may not run for a long time, if it is not overheating why are you concerned.

see if this link helps you out.
sensor camshaft position of hyundai sonata gls 2010 2 4 4 cylinders Google...

To remove and replace a radiator is a major mechanical job, requires some quite complete equipment and some mechancal knowledge.
Last time I had my radiator replaced, it took about 2 hours for a proffesional radiator mechanic . Are you sure your really want to do it yourself?

Better then any "explanation", watch these youtube videos:

How to change 2000 2003 Malibu Radiator Part 1 Removal

Radiator Cooling fan assembly repair install Chevy Impala

How to Replace Radiator How to Remove Your Radiator

How To Install Replace Engine Radiator Cooling Fan 2006 12 Chevy Impala

I would vote for the cooling fan theory. The engine thermostat is supposed to open up at 195 degrees and allow the coolant to flow thru the radiator. The cooling fans come on at 220 degrees and when the ac is on.
A mechanic would use a scanner to watch the engine temp and see if the thermostat is opening at 195 and the fans are coming on at 220.

The relay in engine compartment fuse box.
For its exact location and wiring diagram,click the link below:----Hyundai Sonata cooling fan not working http://schematicsdiagram.blogspot.in/2012/02/hyundai-sonata-cooling-fan-not-working.html
---------------This will help.Thanks.

For radiator replacement procedure and radiator problem troubleshooting. I suggest you to click the link below and follow the detailed procedure :-----

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How to Replace Engine cooling Fan on car? http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-engine-cooling-fan-on.html

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Engine makes noise and Cooling Fan belt Breaks? http://howtobyme.blogspot.com/2011/12/engine-makes-noise-and-cooling-fan-belt.html

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Replace Fan Relay but still Radiator cooling fans not working? http://schematicsdiagram.blogspot.com/2011/12/replace-fan-relay-but-still-radiator.html

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Cooling fan relays location? http://technoanswers.blogspot.in/2012/02/cooling-fan-relays-location-on-1998.html----------DIC says "COOLING FAN FAULT"? http://schematicsdiagram.blogspot.com/2011/12/dic-says-cooling-fan-fault.html
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How to replace radiator Cooling Fan?

http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-cooling-fan-on-acura-car.html

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Engine cooling components working?

http://repairhelpcenter.blogspot.com/2011/11/engine-cooling-components-working.html

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How does Vehicles Engine cooling system works? http://repairhelpcenter.blogspot.com/2011/11/how-does-vehicles-engine-cooling-system.html

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cooling fan not working http://schematicsdiagram.blogspot.in/2012/02/hyundai-sonata-cooling-fan-not-working.html----------- Fuel pump relay and cooling fan relay troubleshooting? http://repairhelpcenter.blogspot.com/2011/10/fuel-pump-relay-and-cooling-fan-relay.html

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Why Transmission fluid leaks near radiator?

http://repairhelpcenter.blogspot.in/2012/02/transmission-fluid-leaks-near-radiator.html

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Transmission fluid leaking?

http://technoanswers.blogspot.in/2012/02/ford-windstar-transmission-fluid.html

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How to replace Radiator?

http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-radiator-on-audi-and-vw.html

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HOW TO REPLACE AN UPPER RADIATOR HOSE

http://schematicsdiagram.blogspot.com/2011/07/how-to-replace-upper-radiator-hose.html

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HOW TO REPLACE A LOWER RADIATOR HOSE

http://schematicsdiagram.blogspot.com/2011/07/how-to-replace-lower-radiator-hose.html

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How to replace Radiator on Car models?

http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-radiator-on-acura-car.html

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How to flush cars radiator?

http://repairhelpcenter.blogspot.com/2011/11/how-to-flush-cars-radiator.html

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HOW TO PRESSURE TEST A RADIATOR AND CAP

http://schematicsdiagram.blogspot.com/2011/07/how-to-pressure-test-radiator-and-cap.html

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HOW TO REPLACE A RADIATOR

http://schematicsdiagram.blogspot.com/2011/07/how-to-replace-radiator.html
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HOW TO REPLACE A RADIATOR SUPPORT

http://schematicsdiagram.blogspot.com/2011/07/how-to-replace-radiator-support.html

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This details will help.

Thanks.

well first i would check all the water hoses in the engine compartment for cracks and leaks then check around the radiater for leaks if you don't see any water leaking from the hoses or the radiater then try to see if you see water coming from the water pump behind the cooling fan if the water is leaking from behind the cooling fan then it is most likely your water pump

SOUND LIKE COOLANT FANS HAS A FAULTY THERMO SWITCH LOCATED AT THE BOTTOM OF THE RADIATOR ON LEFT HAND SIDE.CHECK THE FUSES 8 IN THE ENGINE COMPARTMENT AND CHECK FUSE 16 IN THE PASSENGER COMPARTMENT FUSE BOX.WHEN ENGINE OVERHEATING IF BOTH COOLING FANS WORKING.OVERHEATING PROBLEM COULD BE BLOWN HEAD GASKET.CHECK ENGINE OIL LOOKS LIKE MILK HEAD GASKET LEAKING.SEE WHEN YOU DRIVING LOW AND HIGH SPEEDS THE COOLING FANS SUPPOSE TO BE RUNNING.IF THEY NOT RUNNING THAT IS YOUR OVER HEATING PROBLEM.

Possibility of a Thermostat, 1st step for me is to make sure that the Radiator Fans are coming on when its overheating. This will all the electrical part of the problem go away and then you can focus on mechanical parts. If the fans work, replace your thermostat. But make sure you do not remove it when the car has been running. Let it cool down or do it in the morning time.

"Already had replaced: both cooling fans, fan control module, coolant temp sensor, fan switch, 4 terminal connectors. No trouble codes reported in VW electronic diagnostic test. 2 different VW dealers and and my mechanic threw in the towel. Any suggestions greatly appreciated."

This is a common problem with the VW..and no one has an answer WHY. (including VW mechanics)

THIS IS A RECALL ISSUE and should be implemented