Bilge Pump Wiring

[tpenfield]

My bilge pump bit the dust during one of my recent outings with the boat. I accidentally left it on while anchored and it seems to have burnt out the motor. When I checked on it this past weekend, I noticed that there was an indicator light illuminated inside the instrument panel switch that would not go off no mater what I did . . . battery on/off . . . did not matter. So, that got me to wondering about how the bilge pump was wired and if there was some sort of short in the switch. My thinking was that light within the switch would/should only go on when the instrument panel lights are turned on. The light within the switch stayed on no matter what.

Then, I came across this wiring diagram which made sense as to how the light stayed on . . .




Based on this diagram, the indicator light within the instrument panel switch must also be connected to the outgoing power lead of the switch, and also the float switch wire and the instrument wire must joint at the voltage side of the bilge pump. That way, if the bilge has enough water in it to activate the float switch, which it did, then the instrument panel light would go on, as an indicator that the pump was running.

I ended up disconnecting the ground lead at the switch, switch made the indicator light go out, so as not to run the battery down. I subsequently pumped out the bilge by hand, which probably would have made the indicator light go out as well. I had just never seen a bilge wiring & switch setup like this, but maybe never noticed, since this is the first time I had a pump fail.
I think I got to buy a new pump . . . the old one is a Rule 2000 GPH.

 

[gm280]

I am sure it will work that way, but I really don't understand why there is an illuminated switch for that circuit only when pumping. I can understand a illuminated switch to let you know you switched the bilge pump on, but not one that lights only when the pump is working. But if you like it that way, wire it that way. It is just different ideas for different folks. JMHO

 

[tpenfield]

Yes, it seems like it is wired that way at the factory. I could not figure it out at first, but finding this diagram on the web seemed to make sense. I also checked the schematic for the bilge pump switch from Carling Technologies, which my boat has, and the switch has internal connections so that a light will illuminate when the pump is running, either by the float switch or the dashboard switch, and it also has a second light for when you turn the instrument panel lights on. ( I did not know that either)

Of course the illumination when the pump is running is fairly useless in normal daylight, as I certainly did not notice it while being anchored for a few hours.

I think that I will keep the wiring this way as the Gods at Formula Boats intended it.

 

[GA_Boater]

It makes sense in that it is wired to tell you when the pump is on. If you flip the switch you have a reminder or warning to turn it off. If the float switch turns the pump on, you have a warning light that water is filling the bilge.

Some times there is a light to tell you the pump control is in auto mode, but that would require another switch and light.

 

[Grandad]

I don't see anything unusual about the wiring diagram. The indicator light within the switch will come on whether you turn the pump on manually or the float switch turns it on. If your light is on tpenfield, the pump is being supplied power and should be operating. Removing the negative at the switch simply hides the fact that the pump is getting power. You're just losing the indication, so why disable it? If the light is on, the pump is on too. The pump is using more power than the indicator light, so why are you concerned only about the light? It's just doing its job. If the light's on when it shouldn't be, I'd suspect the pump's float is stuck on. - Grandad

 

[tpenfield]

My only concern about the light is temporary until I can get the pump working again. Of course, the pump may be drawing current, even though the pump motor seems to have crapped out.

My plan is to get it all hooked back up the way it should be. Now that I know there is a light that goes on when the pump is running, I can keep an eye out for it. Maybe, I should add a small buzzer to the circuit, since the light is hard to see.

 

[fhhuber]

Yep... that light only comes on when there is power trying to run the pump. Pretty normal.

Sometimes the instrument panel will be wired to have the lights come on when the main power switch is on, to help find switches in the dark. Sometimes they are wired to light up when the switch is turned on.

If you do a buzzer... have that in a circuit to sound when the float switch turns the pump on.

*********************

It is fairly normal for there to be a master power switch that shuts EVERYTHING that isn't controlled by the key switch down...

If the boat is left in the water you have to make a decision.

Do you want the bilge pump to be able to come on and prevent sinking from a slow leak or accumulated rain?

Generally its a good idea. Put a reasonable solar panel on and appropriate charge controller and the bilge pump on a float. Then you potentially avoid:

https://www.youtube.com/watch?v=EDx5FVHg8jo

 

[tpenfield]

I'm hoping a buzzer of some sort will prevent me from leaving it on. I usually flip it on when coming on or off plane as the bow is way up and the water goes back to the transom where the pump is located. The recent outing is when I did that and forgot to turn it off. that is when (I assume) the pump burnt out or something. For all I know, the battery could be drained down from the pump, but I did manually pump about 15 gallons of water out of the bilge that had accumulated from rain, etc. while the pump was not operable.

Although, perhaps the pump would have killed the battery by now, because I think there was enough water in the bilge to activate the float for about a week before I started to diagnose the issue.

Just got to find a somewhat pleasant sounding 'beeper' for the circuit.