Deck light - what's the spare wire in mast?

[Patrick Randall]

I'd like to replace the steaming light with a steaming/decklight combo by aquasignal. I've just taken the plate off under the mast foot (in the cabin roof) and see there are two cables (in addition to the vhf) - one a 3 core and one a 2 core. One of the wires in the 3-core is unused. Does anyone know where it terminates? At the masthead or at the steaming light? (Ever hopeful = thoughts of simply mounting a switch on the aforementioned plate - till I can unstep the mast and do it properly)

 

[Crazy Dave Condon]

investigate

kThe loose wire may be a godsend but you need to know where it ends on the mast ato make sure it is not in use. If not in use nor the bottom is attached to another wire inside the mast, then you could use that as a hot wire. But you will need to tap into the negative wire. If you know what you are doing, proceed.