I own Skoda Fabia Petrol 1.2 MPI, 2009 Model. Since last 2-3 month I am facing inconsistency with my Radiator fan.
Radiator fan works as expected sometimes ( Turn On when certain temperature reached ) and other times not to run even when engine is overheated.
Radiator fan works as expected for an hour or two and then for next few days it wont turn on even when engine is overheated.

When Radiator fan does not turn ON while engine is running on quite a few time, A.C. stops cooling even when set at lowest temperature and after a while Gauge Cluster shows Overheat Symbol, so I have to pull over and wait until vehicle is cooled down.
Engine and AC works fantastic when Radiator fan working properly.

 

There is no guarantee whether Radiator fan will turn on to cool down engine or not. Sometimes it does turn on and other times it doesn't.

What could be the root cause behind this issue and what should be my course of action to identify and eliminate this issue.

Try giving one of the fan blades a little push with a finger next time you think it should be running but it isn't. **Be careful to move your finger away quickly if/when the fan does start spinning**

If it starts to turn with a bit of help it may indicate that two or three of the four brushes are stuck in their holders, not making contact, or all four may have worn down so much that they are now too short to make good contact.

 

Are you in a hot climate?

10 minutes ago, Wino said:

Try giving one of the fan blades a little push with a finger next time you think it should be running but it isn't. **Be careful to move your finger away quickly if/when the fan does start spinning**

If it starts to turn with a bit of help it may indicate that two or three of the four brushes are stuck in their holders, not making contact, or all four may have worn down so much that they are now too short to make good contact.

 

Are you in a hot climate?

Thanks for the suggestion @Wino.
I have tried push starting radiator fan when engine is overheated but it did not help. 
Sometimes fan does start on overheating and runs properly.
When radiator fan is not turned on after running vehicle for sometimes, AC stops proper cooling and later on engine gets overheated.

Yes I live in hot climate. Usual day temperature here is 37 to 45 degree celsius. Vehicle gets overheated very fast, within 20 - 30 mins.

Edited 15 October, 20187 yr by Aniket

I'll think about it tonight and try to help you more tomorrow.