Bilge Pump Wiring

[FreeBeeTony]

My bilge pump is wired using a 3 position switch: on-off-on. I am assuming it's on-off-on (auto).<br /><br />Seems like the float switch is wired through this dash switch. I can't shut the batteries off like this, then the float switch won't operate.<br /><br />In my last boat, I diode-ored the 2 batteries to the float switch...thus I could shut the batteries off and still have power to the pump.<br /><br />Any opinion?

 

[imported_Curmudgeon]

Re: Bilge Pump Wiring

You have to have a double pole/double throw switch; the sides should be separate. Put the manual pump on one side, run the "auto" wire to the other side, then a hot wire from that side to position 1 or 2 on the battery switch. As long as the dash switch is "auto", the auto function is preserved with battery switch on or off.

 

[Silvertip]

Re: Bilge Pump Wiring

Your diode solution will work just fine. Fuse both sides though.

 

[imported_Curmudgeon]

Re: Bilge Pump Wiring

Or you can hot wire the "auto" pump wire to a battery, which means it'll always be hot. I didn't do that it that way because I wanted the ability to disconnect all electrical power.

 

[--GQ--]

Re: Bilge Pump Wiring

Babalon, the way your bilge pump is set-up, it is not a true "OR" logic. Either you bypass the wire to the auto side of the switch or use a single throw (toggle) switch. You already have an automatic (float) switch inside your pump. <br /><br />A true "OR" logic means the switches are wired in parallel. This switch OR that switch will power the bilge pump. Diagram below may be useful.<br /><br /><br />

 

[snowmobilefanatic]

Re: Bilge Pump Wiring

i have never used a bilge pump before but this is my opinion, i thought it whould only turn on when there is water to set off the pump. cause if thats the cause i dont think it whould drain the battery becuase its not powering anything. this was the case with my fuel injectors on my indy 500 snowmobile. the injectors where getting a constant 12V's when the sled was off and the batt is fine.

 

[limacina]

Re: Bilge Pump Wiring

Actually if you have a dual battery system, you might as well run two bilge pumps, one fwd and one aft. Use a double throw double pole switch. Each pump is on it's own pole. one side of the throw is the manual (pwrd on thru the battery switch) Both poles. The other side is not common; but each pumps float switch wired thru. <br /><br />The fwd ones float switch should be 2-3" higher than aft. The float switches (automatic) should be wired to each battery aand to the auto on the dash switch. I ran the aft, primary pump on my hotel laod deep cycle battery and my fwd pump switch on my starting battery. The aft pump handles most instances. If the boat springs a leak and kills the deep cycle battery, you have another several hours to days to get back to the boat and catch the leak. <br />Why not run the two batteries parellel? Pumps fail, clog, break hses, lose connection...<br />Two is real redundancy.<br />I decided this is best after showing up at a beach party to hear a story of a broken sea valve for a guys wash down pump. He was partying next to the boat 200 yards away as it killed the battery and sank over a six hour period. It never went down, just flooded the engine enough to hurt the wallet.<br />Jus an idea, you guys with better drafting programs can draw up a plan if you agree with my idea.