Wiring of shower pump - diagnosing problem

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fishingFINattic

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On my 265 Express the cabin sink and shower drain into a resevoir that is emptied by its own pump w/ float -

It is not working and I am having trouble diagnosing the problem - I am 100% sure that the float switch is working AND the the pump works (removed pump and connected to 12V - used a mutlimeter on float switch).

I just cant figure out how this this is wired - two thinner wires (maybe 18 gauge to the float switch) both black -

To the pump is a one brown (hot) and one black for negative - both probally 14 gauge-

I expected the float switch to be in series with the pump on the hot side, but it is not -

Any ideas on were to go - Checked all fuses on that main fuse panel and they are good -

According the Grady diagram the fresh water pump and other forward bildge pump are wired together according to the one line diagrams - and they both work fine?

Any input would be great - including and explanation of how the float switch works (I am assuming that there is a relay somewere?

Tim
 
Shower Sump

It's not that complicated. The float switch is/should be wired in series with the pump.

Check all your voltages across the pump and at the switch with a voltmeter.

The bilge pumps are on a seperate circuit (they are always on even with the battery switch off). The shower sump is on the switch and circuit breaker panel.
 
As mentioned above, they are wired apart from your main circuit, they are directly to the battery, there could be an inline fuse, or a seperate fuse panel they run to, would have to look at the schemtics to have a better idea. Did you run any new hoses or wires, possibly you pulled a connection out somewhere?
 
It stopped working at the end of last season so I dont think it is a pulled wire -

If wired in series then why is the float switch such smaller gauge wire? And why wouldnt the connection be done right at the pump and float switch location - in other words - come in with two wires, one hot, one ground - and run the hot directly thru the float switch -

This comes in with four wires - two for the float switch and two for the pump-

I wish I have wiring diagram for this thing -

Any other input?

Tim
 
Chase the ground back. A lot of times its a cruddy ground. If you have 12v to pump/switch, it sounds like its not making the circuit. Take a long wire as a jumper and go straight to battery with the ground and see if you can make it work. The float is wired so the pump can come on with the manual cockpit switch as well as the float switch I think. That would explain the multi wires. Grady must wire it so it has redundant operation. Its hard to diagnose wiring without putting your hands on it.

Jim
 
fishingFINattic said:
It stopped working at the end of last season so I dont think it is a pulled wire -

If wired in series then why is the float switch such smaller gauge wire? And why wouldnt the connection be done right at the pump and float switch location - in other words - come in with two wires, one hot, one ground - and run the hot directly thru the float switch -

This comes in with four wires - two for the float switch and two for the pump-

I wish I have wiring diagram for this thing -

Any other input?

Tim
Click to expand...
Are you saying that there are 4 wires out of the pump itself?
If so, there is probably a relay or similar device in the pump.
Let's assume 4 wires.
1. The two that go to the float switch should be connected to each other as close to the pump as possible to bypass the switch. If the motor pumps, the float switch or it wires are bad.

2. The two wires that go to the pump and not from the flaot switch will be battery and ground. Using a different ground connection, verify that there is 12v to the hot wire. If not, there is a bad connection somewhere along the feed ( or a fuse etc).
3. If good , take the second wire and connect it to the new ground. Assuming the float wires from the pump are still connected to each other, the pump should pump. If it does, the ground circuit is bad somewhere. If the pump doesn't work, it is probably bad.
 
Shower Sump

There is no relay. Look on the Grady White site under customer resources. Find your owners manual. It shows 4 wires.

a.) org/blu - freshwater pump
b.) brn/org - shower sump
c.) float switch for bilge pump
d.) brn/blk - ground

The diagram shows the bilge pump in series with its float switch. The shower sump is shown as an assembly but it has a pump and a float wired in series inside it. All three pumps use the same ground.

You probably have a bad crimp or broken wire somewhere in the ground part of the circuit. Does the freshwater pump run?

I could not find a list of fuses but they are located as follows. The auxiliary fuse panel located under the switch panel can be accessed through the 6” access plate in the head compartment. It provides a source of power for electronics in addition to the accessory switches and breakers.
 
I observed the same problem on my 265. Couldn't make sense of it. My solution was to simply tap into the forward bilge positive and negative wires with heat shrink butt connectors. Problem solved. And I think it not a bad thing to have the shower sump bilge pump (500 gph) directly wired to the battery like the forward bilge. The more pumps the better!
 
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