Radiator fan

[night_porter]

Hi all,

 

I have a 2001 Octavia SDi and was wondering which fuse is for the radiator fan?  I have an auto-probe which I will test the fan with tonight, but also wanted to check the fuse was working also.

 

On a side note, I've never seen the radiator fan come on - is this normal for this engine?

 

Many thanks.

[TKW]

Hello,

 

Look in the main fuse box (mounted directly on top of the battery).  There are three green (Edit: 30A, I think) maxi-blade fuses fitted in here, the left-most of which supplies that rad fan and has a habit of melting.

 

While you're in there, check the alternator cable is OK too, they seem to develop a high-resistance condition near the crimp and, over time, will melt too.

 

Is your Air Con working?

 

Where in Kent are you?  If it's East Kent I'm happy to have a look, I've replaced a couple of these.

 

T

[night_porter]

Hi T,

 

Thanks for your reply.  I'll take a look into the fuse and alternator cable as you mentioned, really appreciate it.

 

As for the Air Con, my model doesn't have it as standard.

 

I'm from Maidstone.  I'll report back with my findings this evening.

[night_porter]

Just been out to check, the fuse has continuity and the radiator fan powers up with the auto-probe.

 

I plugged my laptop in with VAG-COM and established a fault with the coolant temp sensor, I'm assuming this would be the reason for the fan not kicking in (at all)?

 

Thanks again.

[mushtafa]

Can you erase the code or is it a permanent fault? Have a look in measuring blocks and see what temperature the coolant is getting up to

[night_porter]

I've tried erasing the code, but after a short while of driving the code appears once again.

 

Could this be the reason for the radiator fan not working?

 

As for looking in measuring blocks, I don't really understand what you mean by this - could you please elaborate further?

 

Thank you.

[mushtafa]

If fault is coming back I would suspect the sensor is faulty. They're not uncommon.

Do you have access to VCDS? VCDS calls live data, measuring blocks.

Sent from Tapatalk 2

[night_porter]

Indeed, fault code is definitely coming back.  I've ordered a replaement sensor.

 

As for VCDS, I only have the lite version.

 

Assumming the coolant temperature is higher than it should be, would the faulty coolant temp sensor prevent the radiator fan from kicking in?

[TKW]

What symptom prompted you to start your investigations in the first place?

[night_porter]

Well, mainly the fact I've not known the fan to kick in.  Just wanted to carry out a health check on it.

[night_porter]

So given that the coolant temp sensor has been diagnosed as faulty, and replacement on the way - is it likely that the fan will spring into life as required once this has been replaced?  Or is the coolant temp sensor unrelated to the fan not kicking in?  Logic would suggest that the coolant temp sensor is the reason behind the fan not kicking in, but I would like this confirmed.

[TKW]

Without A/C, the cooling fan is very rarely needed on a petrol let alone the diesel you have.  Unless you see the needle creeping above 90 degrees, I'd assume all is working as normal.

 

Temperature sender is a very quick and easy swap, as you'll have seen, no need to drain coolant.

[night_porter]

Hi T,

 

That all makes sense, and as much as I'd like to assume all is working as normal it is impossible to rely purely on the needle creeping above 90 given that the faulty sensor prevents the needle from giving an accurate reading.

 

My question still remains as to whether the faulty coolant temp sensor would prevent the fan from kicking in or not....?