Oh Im so dumb... everything is fine now..
I switched + and Gnd from the heater ...and on the Anycubic there must be a connection from the gnd of the heater to the fan ground ... so as long as the heater is on full power there is no real ground for the fan (raised up)... as soon as the pid kicks in the ground comes lower and the fan works.
so i corrected + and ground of the heater and everything works as expected
Many thanks to all of you
Rick