Adding navigation lights and outlet

Hi Kevin,

Can you please help me with a fishing boat wiring question?

I need to wire a Mariner 40hp outboard to navigation lights and a 12 volt outlet.

Can you tell me how I wire the engine to the battery, the battery to fuse panel and then to switches and then to the Attwood navigation lights and outlet? Here’s my boat wiring diagram of what I’m trying to accomplish.boat wiring diagram

Yours sincerely


Hi Louis,

To start with, I would add a ground bus like these on our sister boat wiring site. You may already have on incorporated in your fuse panel.

Here are the basics for your marine electrical switches and 12 volt receptacle.


  • Constant power wire from fuse panel to navigation light switch.
  • Switch power wire from navigation light switch to navigation light.
  • Ground wire from navigation light to ground bus.

12v receptacle

  • Constant power wire from fuse panel to 12v receptacle.
  • Ground wire from 12v receptacle to ground bus.

Hope this helps,