mine "fixed itself" but looking over this thread I suspect it had to do with the contacts.
After the above replies I returned to test it and it worked fine. I can only assume the problem was in the connector in the cockpit having not done anything to any of the wiring.
In over my head?
First Boat, a well-equipped 1977 Camper Nicholson 31
What is all this stuff and how does it work?