Relay

Big Duck, being almost 40 years old, has been wired and rewired by who knows how many owners. My concern today is the VHF. It works fine, but it is on a direct wire accessory bus in the overhead cabinet

and I regularly forget to turn off the VHF when I put The Duck back on her trailer.

The solution is to put the VHF on a switch on the main panel. I have a switch that powers the two GPS/depth sounders which would be a natural for the VHF. This switch is lighted so it's easy to tell whether it's on or off, and I always remember to check this panel when I'm leaving the boat.

The trouble is, this GPS switch is quite a ways away from the VHF and the switch is overcrowded with wires as it is.

My solution is to have the GPS switch control the direct wire bus, so when I turn off the GPS, the bus gets turned off too. And the way to do this is with a 12 vdc Bosch Relay.

This little jewel can use a .15 amp circuit to control a 20 amp circuit and the beauty is all I need to do is pull one small wire from the GPS switch to the relay.

Here's how it's wired:
Disconnect the 12+ wire from the fuse panel and put it on the relay.
Run a new 20 amp wire from the relay to the fuse panel.
Run a small wire from the GPS switch to the relay.
Connect a ground wire from the relay to the fuse panel ground.

Now when the GPs switch is on, the fuse panel is energized. When the GPS switch is off, the fuse panel is off.

And I can now run other accessories - like this fan, from the fuse panel knowing that when the GPS switch light is out, nothing is left on to drain the battery when she's on the trailer.