Bilge pump wiring

jimrockireland

Petty Officer 2nd Class
Joined
Jul 8, 2013
Messages
141
I have a 1983 Mercruiser 305/5L MCM228 engine with serial#6285627. There is a Mayfair Marine bilge pump model 22502 (500GPH Pro-Line) in the engine well. Going into the well are 3 wires in the harness - 2 go to the pump and the 3rd wire goes to what looks like a foot pedal. It is labled Atwood AFS 2000. There is another wire from the Atwood that goes nowhere. I'm thinking this should probably go to the pump somewhere but I'm not sure. Does anyone know how this should be wired up?
 

alldodge

Moderator
Staff member
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Mar 8, 2009
Messages
42,572
Re: Bilge pump wiring

The bildge should be connected direct from the battery and through a float switch back to ground. Most bildges have a secondary connection to a switch where the pump can be turned on from the dash. The foot pedal thing is the float switch. Here is a pic, have a look and let us know if further clarification is needed.

Bildge pump.gif
 

jimrockireland

Petty Officer 2nd Class
Joined
Jul 8, 2013
Messages
141
Re: Bilge pump wiring

I think I can take it from here. I just have to determine if the unconnected wire should go to the pump or the dash switch. My guess is it should go to the pump since it is only about 5 inches long.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,345
Re: Bilge pump wiring

the 2 wires that come out of the float switch ,one goes to the brown wire of the pump, the other goes to the battery thru a fuse. Dont know where you boat but 500 seems a bit small for a 22 footer.To test the pump size, leave the drain plug out and see if the pump handels the flow simulating a broken hose.If your taking in more water than is going out the pump is too small. also consider adding a alarm horn to the pumps brown wire.
 
Last edited:

jimrockireland

Petty Officer 2nd Class
Joined
Jul 8, 2013
Messages
141
Re: Bilge pump wiring

Thanks. The boat I have is a 1983 Wellcraft Sunhatch 196. It is 19 feet long, but once I get it going in the water I will test it as you suggested.
 

UncleWillie

Captain
Joined
Oct 18, 2011
Messages
3,995
Re: Bilge pump wiring

The Bilge Pump is only there to remove Incidental water. Splash, Spray, Spills and Drips.
It will not keep up with broken hoses and was never indented to be a Damage Control pump.
It is 500 gallons an hour, not 500 a minute, and more like 300 in reality.

All 1/2 drain plugs are the same size no mater how big the boat is.
The pump won't keep up with any of them.
 
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