Got in car the other night was below freezing but with in 10 mins on motorway only doing about 60 heater on full pulled up at junction and rad fan kicked in,doing it all the time now.I have a temp gauge fitted and its stays at about 80 its had a new fan, temp, sensor and thermostat in the past twelve months.never used to do and its not overheating just seems rad fan is working hard to keep engine temp down even in this weather any ideas anyone or is this normal thanks

Any water loss?

What coolant are you running?

Otherwise -- the fan is switched on the earth side, so check for any failure in the insulation which could be causing it to come on.

cheers will check the wiring as coolants right not long replaced it and flushed the rad