Sorry Darkness, I missed this question. According to something I came across earlier while looking for something completely different ...

 

 

"It is also possible to test the radiator fan with

the self-diagnosis of the air conditioning

system."

 

 

Presumably that means if you go into the appropriate module in VCDS you can trigger the fan(s) and see them working (or not). Does your car have one or two rad fans?

 

Haven't tried it myself, but it looks like a useful trick.

Well the thermo change has greatly improved the speed at which both car and heating, heats up.

 

 - I have 2 fans.

 

Do you have a link or reference to the vcds talk, ive not seen a method this way before.

It was in here, pdf page 6, document page 49, last sentence. I might get a chance to look into it tomorrow, maybe not.

 

Have a play, there's probably some sort of actuator/output test you can run from within Module 08-Auto HVAC.

I would stop worrying about the fans and the cut-ins. The whole reason why cars have temp gauges and warnings is so that if anything fails you know about it. The switches, fans and control module are pretty reliable anyway

It was in here, pdf page 6, document page 49, last sentence. I might get a chance to look into it tomorrow, maybe not.

 

Have a play, there's probably some sort of actuator/output test you can run from within Module 08-Auto HVAC.

 

Ive had a play, couldn't achieve anything in auto hvac, But in engine module, there is a output test for cooling fans, but i think it just tests the switch. Also is there not a testing option for A/C would have thought that would be in auto HVAC also, Its there in module, but no output test?

This fan test you've found must test the two relays within the fan control module. The only way to test the thermoswitch would be to physically heat it.

AC testing options would only be available with engine running I imagine, did you try that?

Edited 9 March, 201610 yr by Wino

You wont get the engine hot enough in these temperatures to get the fan on. I wouldnt worry about the switch not working tho as even if it failed you could switch the ac on and the fans would go to cool it down.

Even just the heater on hot and fan on full is enough to stop it overheating.

I logged the rally car at 115° on a stage on a hot day and the fans had come on then but thats the only time ive seen them going. Short twisty stage with very little high speed sections so very hard on cooling etc.

I tested the fan switch on my Fabia !,4 one day. Turened the heater off an let the engine go on idling after driving. It took long time before the fan cam on, and it went fast off again, two minute then on and of, an so on... 

The fan must go n if the heater is off I think...