Vauxhall Corsa cooling fan

[Gazza61]

The radiator fan has packed up on my wife's Vauxhall Corsa 1.2. (1997 reg 1.2 litre engine).
Can someone tell me how I can check if it is just the thermostat that is faulty or if it's the fan motor that
no longer works ?
I've had a look at it but can't figure it out and don't have a workshop manual.

[chas2008]

just put a live feed to the motor,WATCH YOUR FINGERS !!! , it wouldnt be the t/stat anyway, more likely to be the water temp sensor which is located in the top of the waterpump. Not 100% sure how the Corsa system works but if it had been a Ford the trick is to take the plug off and short it with a wire/paperclip then if the fan starts its a switch/sensor problem,if it doesnt its a fan problem..

[Panic Button]

Are you sure it's packed up? The weather is not that warm.

[AlBags]

The sensor in the top of a Corsa water pump is a temp sensor. This signals the ECU. It is the ECU that controls the fan these days on modern stuff. I think the Corsa is like this (I may be wrong)
To check if it is an older system, one would look for a radiator temp switch (which switches the fan directly, like a Mk3 or 4 Escort for example, although Ford is in the thermostat housing) is
If there is a good reading on the temp gauge .. centre .. N, then fan should not be running. If it gets up to 3/4 or more, fan should be running. You should test the fan connector plug with a multimeter to see if a value is changing. Usually, 12v will appear to energise the motor.
If the thermostsat was stuck closed (they usually fail open tho) engine would just rise to overheat, and fan would run constantly. System would pressurise up and throw out water or boil in engine.

[Gazza61]

The fan doesn't even start when the temp guage gets into the red so I reckon it's duff. Hopefully it's a temperature sensor that's not working correctly - I'll follow your advice and have a look this weekend.
Thanks for your answers.