Bilge pump questions.

[Burns363R]

I have a small bilge pump underneath my engine. It has a float on it. I lifted the float manually with the key on and off, and it does nothing. I have a button for the bilge pump, and when i flip it, the pump turns on with the switch each time, whether the float is up or down.

Is the right? Under what conditions should the bilge turn on automatically. Say i leave the boat in the water over night, and want insurance its not going to take on water.

 

[Alumarine]

It sounds like the float switch is either broken or not wired correctly.
Or sometimes the switch has a 3 position off/on/auto function.

If you google the make and part number of the pump you can get a wiring diagram.

 

[oldboat1]

Assume you are talking about the ignition key. The pump should not be wired through the key switch -- pump should work via the manual pump switch any time. Not horrible if the manual side is wired through the switch, but definitely should not have the float/automatic side through that key switch. The manual side of the switch can be wired through a toggle, and the float switch wired to the battery or bus (always live). I like to use a man/auto bilge pump switch for control, but a couple of the pumps on my boat have their float switches wired directly (with the manual pump controlled by a toggle). None of my switches go through the ignition. The float switch circuit on yours may have some corrosion, or the switch may be bad. Would trace the wiring and look for good contacts first.

 

[keith2k455]

Before doing to much,if your boat is out of the water just get a hose and see if the automatic comes on. I tested mine this year and wad surprised at the amount of water it takes to kick on.

 

[oldboat1]

operating the pump by hand, as I understand. I'll vote against dumping water into the hull to test a pump. To see it operate in water, better to pull the pump out and test it in a pail.

 

[shrew]

If you are able to lift the float on the float switch, then there is no need to fill the bilge with water. The water will only lift the float switch, so you are manually emulating the same thing. I doubt this is tied to the ignition key. If the manual switch at the helm works without the key, they I assume the dedicated switch works as well.

There should be two hot circuits. The pump should share a common ground. One hot circuit runs to the manual switch at the helm, then other should run directly to the float switch. The positive from the manual switch connects to one lead on the pump and the positive from the float switch connects to the other lead on the pump.

You've confirmed the leg from the helm switch works. I start at the pump. Using a Multi-meter, test the circuit from the float switch to the pump. Then test the positive going TO the float switch. If you get a reading upstream of the float switch, but not the other side, then it is the switch. If you get nothing going TOO the switch, then you need to go further upstream.

Sometimes the dedicated lead is tied to the helm switch anyway. It might be a simple fuse or more than likely oxidized wiring.