fan d9? ramps 1.4

i have tried to hook up my fan to the d9 on ramps 1.4 and sent the g code but nothing happens it will not turn on or off

Which firmware?

Which firmware, and is your firmware "motherboard" set to the correct value for extruder, bed, fan?

Also, one of my fans does not work if the wires are backwards (I would have assumed it would have just spun in the opposite direction). Try reversing the wires

"wont turn on or off"? So does that mean that it does start?

In Marlin (and probably many other firmwares) there are multiple settings for the "Motherboard" - aka the board you're using to drive everything.

RAMPS 1.4 can either be type 33 or type 34.

Type 33 has the following setup:
D10 = Extruder 0
D9 = Fan
D8 = Heated Bed

Type 34 has it differently:
D10 = Extruder 0
D9 = Extruder 1
D8 = Heated Bed

So if you're going to use a fan on D9, your Motherboard setting needs to be set to type 33.

Note: Yes, this means by default, you can't use fans on a dual extruder setup.

I know this is a little old, but I have a fan connected to D9, and there seems to be no power going to this port?

Have I blown a fuse somewhere?

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Regards,

James Simpson

Quote
JamesSimpson
Have I blown a fuse somewhere?

Does anything (besides the heated bed) work? If so, it's not the fuse. Check the connector and the mosfet if everything else works.