Fan for extruder

[terrace_dr]

What is the yellow wire for..Because i need to replace the fan and I have only a two wire 12v fan.
Can i use a two wire fan? Thanks

[russellz]

The yellow wire is for the tacho output. If connected via a resistor to the +ve supply it will give two pulses per revolution of the fan. It can be used to detect the fan speed or just to ckeck that the fan is working. I don't know if your control board uses it but if it does it will signal an error if it's not present.

Russell.

[terrace_dr]

Thanks. I have the GT2560 board on the i3x prusa.
Do you know if this board uses these pulse signals?
Thanks

[russellz]

Sorry, I don't know if it is used. It shouldn't do any harm to try it and see.

Russell

[terrace_dr]

The post above has absolutly noting to do with the question from the OP.
Good grief

[Cup]

Hi @terrace_dr,
You can use the fan if it is one with 12V,and make sure you have the right wiring to the 2 pins("+" to "+" of the connector on the board,and "-" to "-").

[terrace_dr]

Thank you for the help!

[daveapplemotors]

I have a two wire fan and the display shows the percentage of fan speed just as it did with a three wire fan.