Have you configured correct https port in eapps.cfg?
Also you need to set SecureBrowse parameter of OM as well to value 'True'.
You need to ensure that webserver is routing request to secure port.
Please refer following article for further information:
How do you enable secure socket layer (SSL) communications between client web browsers and the Siebel Web Server (SWSE) in Siebel 8? (Doc ID 554303.1)