This is a short post that might help others since the Linode documentation is unclear on this one.
Load balance SSL APIs (HTTPS web servers) running on several Linodes using NodeBalancer. You followed the directions from here and added your Linodes to the NodeBalancer but they wont go UP.
The NodeBalancer needs to talk to your nodes over HTTP. So once you create your configuration for HTTPS, add the nodes and use port 80. That is, if you want to add node 188.8.131.52 (yes, you should only use internal IPs), you want to add it as 184.108.40.206:80
If your experience problems and one of the node does not want to go UP, delete it and start over. I had this problem after changing which port to use etc. and I could not figure out why it would not work. So I deleted it and created a new entry for the NodeBalancer. Also, give it a minute (literally).