Big fan coming on...

[Twiggy]

Largest of the two fans has started coming on from cold up to 90.  Then its intermittent when in traffic, in traffic it can be between 30 seconds to several minutes.

When its been running at normal running temp for say ten mins the car is fine and the fan doesn't cut in.

Is this the thermostat thats causing this? need replacing?

Car runs absolutely fine, there is no excess heat coming from the engine, economy is the same etc.

Any help would be much appreciated.

Andy

[chipmunk82]

Is it when the aircon is running? does the little fan work at all? The larger fan works overtime when the smaller fan stops working.
If not, try looking in the fusebox in the engine bay and F38 relates to the fan. Take it out and give it a clean and see if that helps.
It did when mine looked like it was seized

[Twiggy]

Smaller fan is free moving so but not working when the larger fan is on.

Checked the fuse and all is fine there…

i have the blower on in the car not (econ) temp is currently set to 17. occasionally i do get a blast of cold air 

[chipmunk82]

My fuse looked fine too but for some reason cleaning it up and turning it round the same direction as the rest made the smaller fan start to work again.

[Welshman Adam]

I had this fault.  The smaller AC fan had packed up, apparently quite common.  I think there's a DIY guide on here somewhere.

I had mine done under warranty, it was approx £230 all in.