SQL Server 2014 FCI Add Port
You will also need to configure an additional TCP endpoint inside of SQL Server itself. If you run a query of

SELECT * FROM sys.tcp_endpoints;

I would expect you to see the default endpoint, as well as the Dedicated Admin endpoint. You will need to add another endpoint:

USE master;  
GO  
CREATE ENDPOINT [MyNewTCPEndpoint]  
STATE = STARTED  
AS TCP  
   (LISTENER_PORT = YourTCPPort, LISTENER_IP =ALL)  
FOR TSQL() ;  
GO  


And then you may need to re-grant access to the default endpoint

GRANT CONNECT ON ENDPOINT::[TSQL Default TCP] to [public];

See the Microsoft documentation on configuring SQL for multiple TCP ports for full details.