Re: Bilge Pump Auto or Not
Auto bilge pumps are switched by placing the float switch contact inline with the source.<br /><br />Your forward 3-wire bilge pump is likely designed to be wired into a 3-way panel switch and the pump probably has a built in float switch. At the panel switch, use off to isolate the pump; auto to let the pump make its own decisions; or hold in manual to bypass the float switch to activate the pump. Your pumps wires should be something like: black=common (gnd); brown wire for manual source; brown with stripe (white, yellow or red) for auto source.<br /><br />You should be able to test the pump by applying a voltage source to the brown wire and take the black wire to a common ground.<br /><br /> If your aft pump has a float switch built in it will pump when voltage is supplied only if there is something to pump. Without a float switch it is a simple on/off configuration.<br /><br />You can T off the source wire from the aft pump and place an optional float switch inline with the auto position of a 3-way panel switch on one leg; and run the other side of the T to the manual position of the panel switch.<br /><br />Without 3-way panel switches, you can wire the pump(s) thru ignition activated circuitry so they are available for auto function only when the boat is pwrd on. This prevents an unattended bilge pump from auto starting and draining the battery (bank).
