WHERE IS THE RADIATOR COOLING FAN SENSOR 2008 LINCOLN MKZ

any suggested fixes for this problem? Yeah , view a wiring diagram to see what all is involved in turning on the cooling fans an test with a DVOM - digital volt ohmmeter . Free wiring diagrams here http://www.bbbind.com/free-tsb/ Enter vehicle info. year make ,model an engine . Under system click on engine , then under subsystem click on cooling fans. Click the search button then the blue link . Looking at the diagram i see three relay's - fan control , high fan control , lo fan control . All three relay's are commanded on by ther PCM - engine computer . Checking for DTC'S - diagnostic trouble code's with a scan tool . Double check your work - pinched wiring etc...... check for high speed fan relay stuck contacts .

Has a cylinder head temp sensor located in the end of one of the heads .

I think I may be able to help.
Screwed into the engine block are 2 temperature sensors, which may actually be identical parts, even though they may have a different part number in the parts book.
The function of each is different.
One of them turns on the electric fan to cool the radiator when it is overheating,.
The other one tells the computer what the engine temperature is and adjusts the fuel mixture.
When the "computer" sensor goes bad, the symptoms are identical to yours.
God bless your efforts.

this fans turns on in order to cool your radiator and cooling system, it will also come on when the air conditioning switch is turned on, if this is running all the time then you should have this checked out by a mechanic, if its coming on and off this is perfectly normal

That is pretty much normal, the heater blower fan acts like the radiator does and helps cool the water passing through it by extracting the heat from it. then once the car inside temp warms up it goes back to normal. Nothing to worry about.

My best advice is to ask a local mechanic to have a look for you as the cause could be a multitude of problems but i would suspect that the fact that when the thermostat stuck it has caused damage to the head gasket and you may even need the head skimmed as well so be prepared for a expensive job or trade this vehicle in quick

the temp sensor is right at the top of the head,so if the engine gets up to running temp (even though the rad is cool)it thinks it has a hot spot,so the fan comes on for a minute.then as the "hotspot "goes,the fan switches off.its not a problem unless the fan stays on,then change the sensor.

the electric cooling fan for the radiator will not turn on when the engine reaches normal operating temp, its only supposed to come on if the engine temp goes over the normal temp. (around 220 degrees)
it is normal for the fan to come on any time the a/c or defroster is turned on.

Cooling Fan Temp Sensor is the First thing You Check (with what you have described) Cooling Fan Should ALways come On When The A/C is turned On as A/C Adds A Load to Engine, If Temp Sensor is Faulty it Will Not Give GROUND Signal to ECM >For COOLING FAN >RELAY to Give ground and turn ON The Fan.
There ARE 2 temp Sensors that Serve Different Purposes 1 is for Dash READING GAGE & Or TEMP LIGHT the Other is For ECM or Fan Relay (SAME Thing) you Said>""can disconnect the sensor and fan continues to run" < This Leads me to think you Changed the Wrong One. Not Questioning your Skills Just Here to Help.
TEMP SENSOR FOR 3.1L V6 is Located upper RH rear of engine compartment, near exhaust system. Temp SENSOR for 2.3L Engine is Located in LH rear of engine compartment.
I Hope this Helps Lead you to a NON-OVERHEATING Pontiac.
Good Luck and Have A Great Evening. rejakwilson