Wed, 08/04/2020 - 10:02am
I can only offer a bit of info. The boat has 3 lights, stern ,mast and stem.., so that is probably the reason for three wires. I imagine they should have a common negative.
Wed, 08/04/2020 - 10:44am
Wed, 08/04/2020 - 11:10am
Good to see people helping each other but just a reminder to all that these forums ,unless locked by Rick , are in public domain so members may not wish to post their own contact details. All members should have access to the membership list in members area and that has contact numbers and emails if supplied. Also it is possible to send a private message to another member through our website but that replies on them seeing it.
Wed, 08/04/2020 - 11:28am
By the way, the standard macgregor wiring bring all negatives back to a bolt that is secure through the liner as you say. That is then taken to the negative terminal on the fuseboard. Positives will go to various devices but basic supply would be one circuit for running lights at bow and stern plus one for mast steaming light. If additional lights were placed on the mast then there could be a 3 pin connector on the deck rather than standard 2 pin. Interior lights also on one switched circuit. I found the nut on the bolt very hard to access and tighten properly so I fitted a proper negative bus with each one secured properly . My fuse board takes all the upper deck stuff while for floor level stuff like sockets and pumps etc these go to a master switch near the steps and have individual in line fuses.
Hope that's helpful.