Ramps 1.4 Fan

Following posts found in the forum I have tried to connect a 12V DC fan to D9

My problem is I'm only getting 18 mV on D9
Now I get 18 mV on D10 until I send the pronterface signal to heat then it goes to 12V

I tried sending M106 Sxxx where xxx has been 0, 1, 5, 128, 150, 250, 255 and nothing the fan never comes on

What am I missing ?

Thanks in advance

Do you have your motherboard properly defined in your firmware? I know that if using Marlin, and with motherboard set to "34", D9 is assigned to a second extruder and the fan output is routed to the servo pins.

Thank You
I keep forgetting the Arduino and firmware side of things

was it my motherboard was 34 now 33 and the fan is working well

Thanks