Overheating issues

[R6fitness]

Hi all,

After searching through numerous forums and youtube videos I can't pin point my exact problem causing the car to overheat. I'm hoping someone maybe able to help and save me replacing multiple parts and spending a fortune.

I have a 2002 VW Polo 9n 1.4 BBY engine (has AC)

Current issue:
Once engine gets up to temperature it will sit at 90 degrees for 5/10mins and then proceed to overheat. The fans do not turn on at all. When overheating the top radiator pipe is very hot and the bottom is completely cold.

What I have identified:
All fuses appear to be ok and I have changed them anyway to make sure.

At first I thought the issues was with the Thermo switch in the radiator, I unplugged the 3 pin connector and jumped the wires together. Speed 1 seems to turn the fans on no problem (This could indicate a problem with the thermostat switch?), however, speed 2 does not start the fans although the Fan control module does make a click. (This could be a problem with the FCM? or the fans themselves?).
When I turn on aircon in the car the fans do not come on, (again could be an issue with FCM?)
I have ordered a new thermostat switch and FCM and awaiting delivery but did some other tests as well:

I also tried giving power directly to the fan, it seems to run on one of the speeds but then nothing on the other. (again pointing to a faulty motor?)

Whilst the car is heating up the top radiator hose gradually heats up as well, so this would indicate the the thermostat on the engine is stuck in an open position? If it was stuck closes I would have thought the top hose would also stay cold? However even when the car is overheating the top pipe is very hot and bottom radiator pipe is stone cold? Could it be a block in the radiator? This could also be why the thermostat sensor in the radiator is not sensing heat to turn on fans?

I know the water pump could also be an issues, how can I diagnose this? The blowers in the car work fine and blow hot air.

My trouble is I seem to have symptoms for different issues... Whilst I appreciate it may be that I have multiple faulty parts I wanted to reach out to see if anyone could advise?

Thanks in advanced,
James

[Crasher]

Replace the complete thermostat assembly