I think the diode on the circuit board is blown. Whether the switch is turned to "Anchor Light" or "Steaming Light", both circuits are live. There was a lightening strike on the mast of a boat a few slips down which fried the inside of his cabin and blew out my knotmeter/depth sounder, so I'm suspecting that's the cause of the masthead light problem, too. Regardless of the cause, it appears that my diode is out. What are the specs so I can get a new one?