Vasoline is oil based, so tends to cause overheating. Use KY jelly instead or even a bit of washing up liquid.
Hucknall Notts if possible is it possible to just connect the fan to battery so its on all the time??
and would a paperclip across the sensor connectors cause it(fan) to come on??
The Light only comes on for a second or too Im going on a bit of a run tommorow so Ill see what happens thanks for all your help!!