I have a A3 3.2, 2004.
My coolant temperature gauge on the dash now does not move and just reads zero and my radiator fans run all the time.
I have changed my coolant temp sensor and it made no difference.
I have noticed another exact same sensor on a large hose on my radiator should this be changed aswell ?
Please help.

If I recall the sensor in the hose is the fan control sensor, the one near the back is ct sensor, And they are different colors ... get the right one for the ct sensor... dealer has them for around fifteen dollars or so