Help needed changing to secondary featured img on hover

[ghost]

hi there! i've been trying to change the thumbnails of my post's featured images to the secondary featured image on mouse-hover.

installing the multiple post thumbnail plugin worked fine, i can select a secondary image but i'm having trouble implementing that hover option/effect.

SUMMARY: -theme: Salient -plugin for secondary featured image: Multiple Post Thmbnails (https://de.wordpress.org/plugins/multiple-post-thumbnails/) -tutorial i tried to use: http://www.scratchinginfo.net/hover-two-featured-images-wordpress-via-multiple-post-thumbnails-plugin/ -link to my texting-site: http://feeluna.com/offline/ -problem: when i hover over one of the thumbnails, i want the secondary image to appear, currently only the posts named 'TEST...' have a secondary thumbnail selected.

we would be grateful for help and would like to pay you back for the favour!

here's what my clean index, header, functions and style looks like: support-themefiles.zip

[chrisscott]

If you can post code samples with only the thumbnail registration portion from functions.php and the output in your theme's template it would be helpful.

[ghost]

@chrisscott thanks! i posted a zip with my theme's code... i posted this portion in my functions php:

if (class_exists('MultiPostThumbnails')) {
        new MultiPostThumbnails(
            array(
                'label' => 'Secondary Image',
                'id' => 'secondary-image',
                'post_type' => 'post'
            )
        );
    }

i experimented with one of the twentyfifteen themes, and i managed to include the second image in there. so the problem is that my second image is not displaying on the salient-theme.

i used your plug-in in hopes to archiving a hover-effect such as: http://www.floriasigismondi.com/photo/ where a second featured image will only be displayed upon mouse-over. i read it should be possible with additory jquery script. :(