Get thumbnail with CPT-onomies @ luizhrqas

    <?php
// i will use the global variable $wpdb
    global $wpdb;
// i get all the terms from taxonomy 'solucoes' with the ID from the loop
    $solucoes = wp_get_object_terms(get_the_ID(), 'solucoes');
// Loop
    foreach($solucoes as $solucao) :
        // I get the thumbnail_id from the term
        $solucaoThumbnailId = $wpdb->get_results('SELECT meta_value FROM wp_postmeta WHERE post_id = "' . $solucao->term_id . '" AND meta_key = "_thumbnail_id"');
        // If my get is TRUE
        if($solucaoThumbnailId) {
// I get the relative URL from the upload inside the wp_postmeta table
            $solucaoThumbnail = $wpdb->get_results('SELECT meta_value FROM wp_postmeta WHERE post_id = "' . $solucaoThumbnailId[0]->meta_value . '"');
// And use this. :)
            echo '<li><a title="' . $solucao->name . '"><img src="' . get_template_directory_uri() . '../../../uploads/' . $solucaoThumbnail[0]->meta_value . '" width="50" height="50" /></a></li>';
        }
// End loop
    endforeach;
    ?>