Yes, if the disconnect failed, or the battery feed wire connection at the bulkhead came loose(red wire), that is the same scenario that I had, which is running a charging system without a battery. When you said all of your lights blew out, I knew your battery connection failed.
Do the alternator charge stud to battery or starter relay wire. Bypass your 2 bulkhead male/female spade connectors (the big black wire, the big red wire) by drilling right through and running a #10 through the hole. Get rid of the amp gauge.
If you run a disconnect switch, make sure it kills your alternator too and not just disconnect the + battery post.
