Checking Electric Fan

Hiya,
I have an electric fan fitted to my 300 TDI, during the colder months I had my Radiator cover fitted and on a couple of occasions the temp gauge was really high, however the electric fan didn't kick in, what's the best way of checking if it's working ok?
Steve

Run some wires from the battery to the fan terminals and see if it works.

More likely it is however you are switching the fan on. Leccy fans are non standard, so you'll need to hit Google and learn what you have or look at replacing some bits.

After a long cold winter could be stuck and in need of a bit of lube. Mine was.

Car got air con?
Got any extra switches on the dash?
Got anything extra in the top or bottom rad hoses?

The sensor is connected in the top hose, can't see any extra switches anywhere.
It doesn't look like there are is any way to adjust anything on the sensor either, not sure what temp its supposed to kick in, but the gauge was really high!

Is the sensor a curly wire type or a real sensor type?
remove sensor, take a kettle out and put it on to boil hang or drop sensor in and see it the fans kick in put a thermometer in the water to tell what temp it kicks in.
If it doesnt fire up the fan then you need to check some more

Not sure if just bridging the sensor would switch on the fan as dont know what you have.

J

Post pics of fan install including the thermostat fitting. If std resistive potentiometer type [adjustable], it may be it needs setting correctly for a std Defender thermostat/engine running temp setting...

Never understood why the sensor is sometimes fitted to the top (intake) hose.
I would be more interested in checking the coolant temp on the way out and if it wasn't getting sufficient cooling by natural air-flow THEN the fan kicks in.
Certainly that is the way mine was set up with the X-Eng sensor (plus over-ride & isolation options).

@Litch , it makes little difference on a car engine where the flow and return water cct is of such short length. Key is for the the cooling fan to 'kick in' at the right temperature. General design is to have temperature control of the input to ensure cooling is 'ON' with water flow in :. providing cooling water at the correct temp'...unless of course one drives a Triumph Stag

Just fit a viscous fan and be done with it
Grabs coats and exits rapidly........