Radiator/coolant fan won't go off

[aidanmorris]

Hello there

My 480 Celebration has developed an annoying problem of the radiator/coolant fan coming on (at about 87-90 degrees according to the info centre) but then refusing to turn off.

Once the fan has come on the only way for me to prevent a flat battery at the end of a journey is to lift the bonnet and disconnect the plug to it. Ive been leaving it disconnected but that means I'm currently driving around praying I don't get stuck in traffic as if I do I soon have to pull over, lift the bonnet and reconnect. Hardly a long term solution!

Anyone any ideas? My thought was a fault with a temperature sensor.

All advice gratefully received!

Aidan Morris

[Espada]

Short answer, Yes.

If the wiring diagrams in that well known book are correct, it looks like the thermal switch is the only other component in the circuit.

If that is not the case, the only other possibility I could think of would have been a fan motor relay not releasing.

Regards

[doingitsideways]

Does it definitely not switch off after a few minutes of no engine running?

My Celeb's fan runs on for a couple of minutes after switching off, especially after a good pasting or sitting in traffic for a long time.

Steve

[spree]

I have a working switch you can have for a fiver plus postage if you do decide you want to change it.

I removed it as I thought it was faulty but it turned out to be a broken wire...!

[aidanmorris]

Thanks for the advice, I've left the fan running to see if it will switch off of its own accord for as long as I dare without flattening the battery but after a good 10 minutes it was still going and starting to annoy the neighbours! I even left it disconnected for a good few hours the other evening but when I plugged it back in it came on straight away so I think it has to be the switch. Mind you it didn't come on when i reconnected it in the morning prior to venturing out into rush hour traffic so it seems to be an intermittent fault. Haynes says that the switch is most likely to fail open circuit which would result in the fan never coming on where as mine seems to have failed closed circuit or at least be getting stuck in that position.

Spree - I'll take you up of the offer of that switch. If you've got a paypal account send me a PM with your email address and want the postage will be.

Lastly, how do I get to the switch to replace it? Is it a obvious with the radiator front panel off?

Aidan

[spree]

It is pretty obvious once the nose cone is off. You will need a large spanner for the actual switch. I had to use an adjustable one and it was a nightmare. You don't need to drain the coolant if you plug up the hole quickly after removing it and then just top it up a little. I had to remove the battery tray to disconnect the wiring from the switch. It's all much easier on a car without the horrible air con plumbing.

I will pm you my PayPal details! J.