Jordn76

Sounds like that might be the ticket to me. Still waiting to get the car up to have a proper look under there but I’ll let you know what I find. You’ve been a great help so far. I’m a mechanical engineer by trade so wires and electricity have always been black magic to me.

Currently, I can’t get the fault to replicate. It’s been a dry afternoon. Leading me to believe maybe water ingress into the fan plug or controller? I’m in South Somerset so a lot of country lanes and puddle splashes. I’ll leave the fuses in and see what happens as I’m sure it’ll be back when I don’t expect it.

Fuse 24 is good, had a look at all the fuses and none are blown. Waiting for the fan to start up again now as it’s taking longer than normal.

It does seem strange that it only happened in the wet. Seemed fine before. I still need to get the time to get it up and under-tray off to have a look at the plugs to the fan. I’m sorting of hoping it is a case of contact-cleaner. Water displacing plug lubricant and good to go. I’ll check the air-conditioning pressure and pull F24 and see what happens.

I did indeed mean 25. Typing on phones 😓 haha. Not too sure just yet. I will try as I pulled random fuses before to see what worked. Refrigerant as in a/c? I’ll check the pressure on there too then.

That would be a great help thanks. Definitely 24 as it’s the big 40amp fuse. Doesn’t make any sense to me. If I leave the fuse out and run the engine I get the PAS light and the handbrake light flashes. What is confusing is that the fan will still run once the engine is on, even with the fuse pulled. Not sure if there’s a separate circuit for turning the fan on once the air-conditioning is running maybe?

I’m pretty sure, nearly caught me out before on the dashboard fuses when sorting an indicator fault. I do wonder why they don’t change the documentation when it’s for the British market haha.

There’s one large cooling fan on the back of the radiator. I’m pretty sure it’s the only one on this car at least

It’s currently driving me mad. The only way I can isolate the fan is disconnecting the battery or pulling fuse F25 which is labelled as ABS pump. Although I’m sure the fuse box diagrams are vague as to what they power purposefully.

As far as I’m aware it isn’t a DPF engine as it’s 2010? There’s no lights coming on suggesting dpf regen. I’ve had the ambient temp sensor off, cleaned, seems ok. Live data wise the coolant temp sensor seems good, slowly rises to operating temp. It goes on every time I turn the ignition off after a small delay and goes off as soon as I turn the ignition on. So I guess it’s going fail-safe or shorting when there’s not Ecu input or possibly a relay problem. Next step is changing the fan out I guess and seeing what happens.

Hi, first post here. Sorry if it’s been covered before. I have an Octavia II estate. 1.9tdi pd. Randomly today the radiator fan was on when I left work. Full speed so very noisy. As soon as I turn the ignition on it goes off. Temp gauge shows normal at 90 degrees. Wondering if there’s any common issues that come up? It’s been a very wet few days but the fuse box doesn’t seem too wet. I have seen somewhere something about the ambient air temperature sensor could be faulty making it stay on? Had a look the loom seems fine as does the sensor. Probably worth a change for a few pound. Otherwise am I looking at a relay replacement or fan change? I fix aircraft rather than cars for a living so any help would be appreciated.