Hey @Tommy H,
Can you follow the Cable of the Fan to the PCB board?
Look for the Molex connector that is Labeled with the Letters JB. JB are the connectors of the Fans.
Make sure they are outputting 24V. If you do not have a meter then you can try connecting the fan into another JB connector located on the same PCB.
Another way to be able to troubleshoot the Fan is to find another 24V fan to plug into the connector to see if maybe you have a bad fan.