As to a possibly more rounded approach to the solution now that it is more clearly represented than in a previous related thread:
Code:
<?php
$manufacturers_name = zen_get_products_manufacturers_name($product_info->fields['products_id']);
?>
<a href="<?php echo zen_href_link(FILENAME_DEFAULT, "manufacturers_id=" . zen_get_products_manufacturers_id($product_info->fields['products_id']), $request_type); ?>"><?php echo zen_image(zen_get_manufacturers_image($product_info->fields['products_id'])); ?></a>
This is untested, so may have some error(s)...