Wow, I stand corrected...many times over. I wish you'd been around last week. Yours is the most authorative info I've gotten on the subject since I got into my situation...that includes advice from Furuno and B&G.
Anyway, the fellow from B&G was being very helpful or trying to be, sensing (correctly) that I was not getting anywhere and told me with equal vigor that I was barking up the wrong tree...that the h3000 expected data from the GPS to be delivered to the NMEA IN jack. There are only two wires, and that the + out from the GPS should go to the + IN terminal. Well, OK, but it doesn't work. That's when the discussion got around to what a dope I was and maybe I got the NEMA jack and RS232 Jacks confused. I concluded that he was at least partially right.
I didn't mean to sound like I had the last word, and I apologize for that.