Driving to work this morning I got stuck in a minor traffic jam. With horror, I watched the temperature gauge start to rise above half way. Something it has never done before. By the time I got into work the gauge was almost to the hot mark, but the engine was running normally, and no steam rising from the bonnet. She’s got all day to cool off. I know the coolant level was correct, I checked it at the weekend. I don’t usually get caught in traffic jams, so I wondered if the fan doesn’t work when required. Is there a way to tell the engine management to turn the fan on, to test it?
With the ignition on but the engine not running use a short piece of wire (or paperclip) to jumper the GND (GrouND) pin to the TFN (TestFaN) pin in the underbonnet diagnostic box (Located on nearside inner wing). Make sure you are clear of the fan when testing it!
TFA not TFN - Memory fail, sorry!
I don’t have a TFN, but I do have a TFA pin. Is it that one?
Doh! Yes I meant TFA, sorry! I’m blaming old age and a failing memory.
Excellent. Many thanks. Think of me at lunch time, when I go over to the car park just to check if she still has a radiator full of water!
Did it work?
I tested the fan using the diagnostics box, and also by shorting to earth the wire to the fan switch, (on the top of the thermostat), and both methods switched the fan on. So I had to assume that the fan switch itself was faulty, so I’ve replaced it. All I have to do now is find a traffic queue on a hot day and sit in it, and wait to see if the fan comes on!