Multisite SSL Implementation

I'm trying to implement SSL on a multisite installation, but can't make the admin resources load using https.

I was getting a lot of Mixed Content errors on the backend of my site. But now my WP Dashboard returns - Too Many Redirects errors.

I've tried to use the default .htaccass and disable plugins via FTP but doesn't help.

However, the front-end of my site works fine and I'm also able to login to my subsites.