i had the same problem...
thought i'd followsome of the advice on the forum, and ignored it...
then the light would come on from cold...
thought if i'd fill up the water tank (which i was told by my local vw garage is a small round ball type with a back cap)
filled it up, problem went away, and thought to myself that was easy....
but i was wrong, car started over heating wildly, so i kept filling up...
the fan never came on, and today the car steamed up on the A406...
ive put about 20L of Evian water in the car in the last 2 days...
im now geting desparate as the car wont go anywhere without it over heating...
is there anyway to test the fan??
or is there any reason why this is happening??
thanx guys