You folks are awesome! Thank you for the support and help! I really appreciate it.
There was a blown 30amp fuse just past the battery but under the trailer (see attached, barely noticeable at right in photo. Grounding at left in photo.). I had to crawl under the carriage to find it. Are there other hidden fuses I should be aware of? And, should I pull this fuse when storing the trailer to preserve the battery? Seems like they should standardize all things electrical...or would that make this too easy