Hay! That was my concern, im not sure the current output of the AND is sufficient to drive the mosfet, altough in simulation it seems to be. I will soon find out when my supplies arrive...
I just came across the term TTL mosfets, not seen or heard of them before, are they able to switch say 3A?
I also thought of putting a transistor in C - 12v switched E - mosfet gate and B AND output, it then got me thinking, i tried to drive the transistor from the fan signal an ddo away with the AND gate, but it wont work in simulation