I have a SharePoint Server 2013 web application that has been extended to a domain name with both http and https AAMs. If a user runs a search on the http AAM, the search results do not show previews of pages, presumably, because the iframe is pointing at the https version of the site (that's what it showed when I looked at it with chrome dev tools). If the user runs a search either internally (authenticated) or on the https AAM the search result page previews work as expected. Also, when I changed the URL for the preview iframe from https to http using the dev tools the preview showed up. The search crawler is crawling the internal domain name and not either of the two extended AAMs. How can I fix it so anonymous users on the http AAM will see the page previews?
For this I think it matters what the private and public URLs are and what the crawler is trying to crawl. I have switched from https to http for the "main" AAM on this site and pointed the crawler at the http.