Hi. I know this is long time ago but,
I have a 2013 Hyundai i10, It has a single fan, which comes on with the ac on but not when the car gets hot. I checked via diagnostic, no error codes and the temp reaches 90 degrees and the overflow start boiling. fan still not kicking in. I replaced the water pump and the radiator and the coolant temp sensor.. I can feel that the thermostat is opening up as both pipes gets hot after I while of idling. nAs soon as I switch on the ac the car drops to 87 degrees celcuis. Any advise please. I don't see a second sensor on the radiator.

 

Disconnect the coolant temp sensor
Does the fan turn on?

System should be designed where if the sensor dies that the fan would turn on to prevent overheating and head gasket from blowing up
So if it doesn't turn on then need to get electrical schematic and find out what is controlling the cooling fan.
Sometimes it is a relay. Sometimes they use a module. I don't know.

 

Hi.
Thank you for the fast response.
I drove with the exact same car today and had my diagnostic on this car. With the aircon off the cooling fan only kicked in at 103 degrees celcius.
While driving around ac off the temp stayed at 90, 91,89. Ac on then it ran 88,90.
Why would the car water start boiling in the reservoir at 91, my car now I mean. Is it not bleed right or is the reservoir cap faulty.

 

There is a good possibility the cooling system has air trapped in it. There is a special procedure to remove the air when refilling the system. One way is to loosen one of the highest coolant hoses n top of the engine, so the air can exit or you can use the procedure to do this. Just google, "Removing trapped air from a cooling system" . There are several videos showing the procedure..

 

Hi why is my 2010 i20 fan blowing in the wrong direction?
and how do I fix it

 

Before anything can be suggested, was any work done to the cooling fan system. recently?
If the wires to the fan motor are reversed ,that could cause it to run in the opposite direction.

 

2004 Hyundai Elantra
My Temp Gauge seems to work but my fans are not coming on unless I turn on A/C (Passenger Side Fan only)
Turn off A/C and Passenger Side Fan stops.
Driver side fan does not come on.
A/C blows cold chronically (I am sure there is a pattern to the cold A/C and has something to do with the fans but just not sure)
If I rev the car to a constant 2,000 rpms, the rpms drops to around 1,200 rpms and then back to 2k rpms like a teeter tooter.
Can I rule out Coolant Senor since my Temp gauge seems to be working?
if that is ruled out, what is next. I have replaced Cond #2 relay

 

This is when a schematic diagram comes into the picture Some systems have a coolant sensor , a coolant sending unit and and coolant switch to turn on the fans.
Don't know exactly which set-up your vehicle has. Evidently one of them is sending a "Hot" message to the PCM and some vehicles have a strategy to increase RPMs when the engine is idling and getting too warm.
Some will also increase RPMs if the charging system is not putting out enough to keep system functioning.

 

2001 to 2005 Elantras have similar schematics.
My Haynes manual says to check fuses and check power and ground to the fan.
Also check the fan itself to see if it can spin freely (careful that it doesn't turn on and catch your fingers,safety first)
It leads me to believe that if the AC is turned on then both fans will turn on.
Also if the engine coolant temp sensor is disconnected then both fans should turn on
The ECM provides ground for the engine main control and radiator fan relays
Check relays also.