Yes, another cooling fans thread

[chevmat08]

POLO 9N 04 92K Miles
1.9TDI

I noticed yesterday my cooling fans (both) do not operate under anycircumstance. (Engine to temp, key in ignition with cabin fans on etc)

Earlier this year I had to swap out the ECT as it was misreporting engine temps, but I didn't know if the fans were working prior to this. Of course air con doesn't work, but I don't know if that's related or separate.

Checked fuses on the battery, seemingly all in good nick. Fans spin with ease when I manually twirl them. Not sure where to start looking as the topics are endless and causes seemingly also endless. Any advice is super appreciated

[RUM4MO]

First of all, you really do need to Google thins maybe including VW Golf in the search phrase as all these cars across the VW Group marques have the same system and so issues.

That will give you some schematics of what does what and let you work your way through the system.

From your description, as long as the AC is fit to run, ie gassed up okay, then the common item other than the fans is the cooling fan control module.

By the way, there is a thermal switch in the cooling system that controls the fans wrt to coolant temperature controlling, the ECT is completely different function.

[chevmat08]

I've sleuthed through hundreds of posts (pd100 cars and 99-07 vag models) all reporting similar or same symptoms but not a single one ever gives a good starting point, I was hoping for a bit of direction before I started! Also, lots of different causes from bad wires, grounds, sensors, bushes and relays!

Re:ECT I was just mentioning I recently changed this and. It's the last repair carried out as often people will note if I've changed or done anything recently(not to imply it was related). But also I am noting I hadn't noticed prior whether the fans were operating either.

I have been toying with just replacing the control module as it's easy enough to get to and about £16 on gsf atm. But I don't want to if it's the wrong direction, if you get my drift?

[RUM4MO]

From the online guides you should have found that first you should remove the thermal switch and short 2 wires to check the first fan and another 2 wires to check that the fan can be made to run, if they do it is the thermal switch that is to blame, then disconnect the fans power feeds and supply them with power from a suitably fused 12V supply, if they run then the fans are okay, so that leaves wiring or the fan controller in most cases.

I still think that if you have the capacity to do all the above you should have worked all that out from reading online info on this, so maybe it is time to get professional help before spending money on spares in a random manner.