I have used a servo for auto level before switching to inductive sensor.
Check the picture, you can see where the servero is connected.
Place a a jumper like you can see in the pruple circle, do not forget this!
Edit: Sorry i didn't realize you are using those pins for extra fan's, i can't help then.
Why don't you order an inductive sensor? its much more user friendly, you buy them for like 2 euro's.
Edited 2 time(s). Last edit at 08/31/2016 11:05PM by Govahnator.