EBB 2209 + 3 Wire Fan

[Sandman50]

I have a BTT EBB 2209 connected to a M8P + CB1. Running Klipper on a Voron 2.4v2

Intention is to use a 3 wire hotend cooling fan with the tachometer feedback to shutdown the hotend if the fan fails.

Just getting it all up and running now. I finished the mechanical and wiring yesterday.

The cooling fan is wired into the PWM output on the EBB. PWM isn't used as this is a 3 wire fan and I don't need to control that fans speed anyway. (I think?)

Problem: The fan is running all the time.

The fan is reporting RPM, so that is good.

relevant config section:

[heater_fan hotend_fan]
# Hot End Fan
# Fan PWM
# max_power: 1.0
# kick_start_time: 0.5
pin: !EBBCan: PB14
tachometer_pin: ^EBBCan: PB15
tachometer_ppr: 2
heater: extruder
heater_temp: 40.0
fan_speed: 1.0

Fan reports ~8700 rpm which is about correct for the fan. (8500 on the spec sheet)

https://media.digikey.com/pdf/Data%20Sheets/Sunon%20PDFs/MF40101VX-1000U-G99.pdf