Service stops responding after switching port to 443

I tried to set up https, and changed the port in to 443, but when I try to access it, the site is no responding.
I’ve also set up:
SSLCertificateFile /etc/httpd/conf/ssl.crt/cert.pem
SSLCertificateKeyFile /etc/httpd/conf/ssl.key/certkey.pem
following instructions from: RT SSL implementation - #5 by Drew_Barnes, but I must have missed something or there was a step that was not included in that post.

What do you see in the web server logs?