Create search box on Archive Custom post type

In your template_search_spec_needs.php, remove the custom query. The parameters in your url (s=&post_type=spec-needs-res) should work with the “normal” loop just fine.

So try changing your template_search_spec_needs.php to something like this:

<?php

    while ( have_posts() ) : the_post();
  ?>

        <div class="span4 spec-needs-list-single">
            <div class="spec-needs-title"><?php the_title(); ?></div>
            <div><?php the_excerpt(); ?></div>
            <div class="plus-btn-spec-needs-cont"><a href="https://wordpress.stackexchange.com/questions/299191/<?php the_permalink(); ?>"><button class="plus-btn-spec-needs">+</button></a></div>
        </div>

  <?php
    endwhile;

And you should be just fine 😉