Cooler fan running.

2004 TD4 Commercial.

Parked up the van 4 days ago. Went out to the garden this morning and I could hear a fan running. The van was sitting in the garden locked up with the keys in the house and the cooling fan running fast. Got the keys opened the door started the engine fan still running, opened bonnet to find the fan on the right was running fast. Disconnected the fan and I left it for an hour with everything switched off, when I reconnected the fan it started up again. Help.

If the engine is hot the fan will run after the engine is turned off, so maybe there's a faulty temp sensor - but if there's 2 and only 1 is going then either the other is broken or its not the temp sensor - in which case it is presumably a wiring fault.

Not sure where it is on TD4, but maybe you could pull the wire on the temp sensor and see if the fan stops?