Configuring Zen Cart to work with SSL
If you already have your own certificate for your domain name, you need to edit the following files of your Zen Cart script in order to make it work with SSL:
To access those files, we suggest that you use the File Manager service in your cPanel account. Navigate to the location of the files and select them, then click on the Edit button at the top of the screen. Locate the following code:
// Use secure webserver for checkout procedure?
The domain.com is the actual domain name that is assigned for your Zen Cart website. You need to change “false” value for the SSL to “true”.
Note that there is a difference between www.domain.com and domain.com . It depends on the certificate that you have purchased so make sure that you enter the correct value in the configuration file of Zen Cart