Where is earth?

[chriscraft]

Noithing is simple is it? I've just bought a replacement 3-way 12v switch for my bilge pump. Unlike the previous one which had 3 terminals, this has a fourth, marked on the wiring diagram 'ground'. Now, should this be wired to the negative terminal of the battery (the pump itself already has one terminal connected to negative battery terminal), or is it really an earth. How do you connect to earth on a fibreglass boat?? Will the switch work if I don't connect this terminal to anything? Any advice gratefully received.

[Chris]

Originally Posted by chriscraft

Noithing is simple is it? I've just bought a replacement 3-way 12v switch for my bilge pump. Unlike the previous one which had 3 terminals, this has a fourth, marked on the wiring diagram 'ground'. Now, should this be wired to the negative terminal of the battery (the pump itself already has one terminal connected to negative battery terminal), or is it really an earth. How do you connect to earth on a fibreglass boat?? Will the switch work if I don't connect this terminal to anything? Any advice gratefully received.

The ground is needed to light up an LED in the switch. You don't need to have it connected however if you do then you need to run a wire to the negative busbar or neg terminal on the battery.

The other 3 terminals are your common power then switched 1 & switched 2 (manual & Auto)