Odd bilge pump behavior (shower sumps 400DA)

Stee6043

Well-Known Member
Jun 1, 2015
6,706
West Michigan
Boat Info
1997 Sundancer 400
Engines
7.4L Gassers
Greetings all. I hope everybody had a stellar weekend of boating. I had a near flawless weekend on the boat until yesterday morning during the admirals shower time.

The drain in the shower stopped working (mid-shower, unhappy wife) so I quickly pulled the covers off both shower sumps to find both were inoperable. I fiddled around, jiggling the wires, moving the floats up and down repeatedly and looking intently for an in-line fuse that would have stopped both pumps. I also checked my breaker(s), not thrown.

I finally told my wife to continue showering since the emergency bilge was working fine. While the water was pouring out of the sump box I jumped on Club Sea Ray to research. At that point, without explanation, the forward shower bilge starts working again. The aft sump is still 100% non-functioning.

Has anyone ever had intermittent operation of both pumps at the same time? They are wired into the looms independently otherwise I would have assumed one bad electrical connection was causing both to be flaky.

I'm going to replace both pumps and both float switches tomorrow. I'll also be cutting back some of the original wire to make new connections. I hope this does the trick but thought I'd ask around here as well. Thanks in advance for any thoughts!

 
When something fails as often as a sump, I'm not that surprised about coincidental timing...

I tired of maintaining two sumps when one of them only does duty for condensate, so I tossed one and replaced the other. I routed the aft head floor drain to the bilge pump in the hold and both condensate lines to the new box.

I hindsight, I wish I had kept two sumps, and linked them together by drilling a hole high-up on the sides of the boxes and placing vinyl tubing between them so the aft box could act as a back-up.

It's still "on my list" to run a vinyl tube from the box directly to the bilge pump to avoid the whole area (and wiring) from getting wet.
 
Pull the pumps and inspect the impellers to see if they are free-wheeling. Then connect them directly to one of your 12VDC batteries to confirm whether they are actually working or not. If they are working, then start troubleshooting your float switches and/or wiring.
 
When something fails as often as a sump, I'm not that surprised about coincidental timing...

I tired of maintaining two sumps when one of them only does duty for condensate, so I tossed one and replaced the other. I routed the aft head floor drain to the bilge pump in the hold and both condensate lines to the new box.

I hindsight, I wish I had kept two sumps, and linked them together by drilling a hole high-up on the sides of the boxes and placing vinyl tubing between them so the aft box could act as a back-up.

It's still "on my list" to run a vinyl tube from the box directly to the bilge pump to avoid the whole area (and wiring) from getting wet.

Funny - I had exactly this thought about connecting the boxes while I'm in there. I assume $10 in parts from WM would do the trick. I may not do it this week but it's going to be on my list.

I'll have to share how this shakes out once I start cutting wires. Still seems odd to me they both went down at the same time...
 
Pull the pumps and inspect the impellers to see if they are free-wheeling. Then connect them directly to one of your 12VDC batteries to confirm whether they are actually working or not. If they are working, then start troubleshooting your float switches and/or wiring.

Will do. Definitely worth checking as they come out of the boat...
 
Be sure you identify and label all the wires before you start cutting them loose. It is easy to mix them up when all you are looking at are loose ends and I've found that the wire color doesn't really match any known color scheme......but if you get lost, if can find a wiring schematic for your boat, the colors on the schematic are what is in the boat.

I would also cut the butt splices out and reconnect them before spending a bunch of money on float switches and pumps. You will most likely find that the cause of your problem is corrosed wires in the butt splice connections.
 
Be sure you identify and label all the wires before you start cutting them loose.

Yes, and examine the whole length of the wire. If in the past someone had wire inside the sump, the color can change/fade from that nasty water.
 
Great tips guys. Thank you. The wire color is really unusual. Mostly browns and blacks with a hint of yellow and orange. Not a red wire to be found. I plan to disconnect one/connect one at a time as I replace them. Assuming there is enough room in the grommet to get a couple extra wires in/out at a time.

I don't believe my pumps are original (not shocking for a 21 year old boat). But I can see the OEM splices with the silicone/water tight connections upstream of the connectors that are closer to the boxes. I'll be cutting out the non-sealed sets for sure.

I just picked up two pumps and two float switches at West Marine. Sub $200 for the whole shot. Hopefully this will get me a few years of showering bliss with only filter cleaning required. Fingers crossed.
 
What a classic boating project. An absolute classic.

So I shot out to the boat last night to replace the pumps and switches. An unusual Tuesday trip to the boat. I was actually looking forward to having some quiet time, drink a beer, work through a fairly straight forward project. Of course that was not what happaned.

First and foremost - my issue was 100% electrical. Once I removed both pumps from their baskets it became immediately apparent what the issue was. Both pumps were wired to the switches with hand-wound connections covered in electrical tape that were LEFT IN THE SUMP BOXES. Hilarious. I had a good laugh. Not so funny was that the aft connection was actually warm to the touch when I grabbed it. I'm not sure this would have ever caused a fire risk but it was unsettling.

So I proceeded to replace all the gear anyway. Why not, I'm already in there. And the existing wires were cut so short there was no saving this stuff at any rate. As I move forward it becomes clear that the new Rule pumps and switches are nowhere near the same size as the set that were in the boat. Much bigger, all around. So I had to do thirty minutes worth of finagling to get the first pump and switch in. No problem, works like a charm. Done and done.

I move on to the second pump, the sump with the 800 (I don't know why these would be different sizes). I do the same reconfiguration as the prior pump, get it all wired up, drop the pump in the basket and PRESTO - the fricken new 800 is a 1/2" taller than the 500, and a 1/2" taller than the 800 that I just pulled out. Good lord. Of course the top won't go back on the sump box with it like this.

And of course West Marine closed an hour ago.

I'm going to go grab another 500 today and swap out the 800. With any luck this should conclude this project. I'll have all of the new connections tied up, out of the way, out of the water. Hopefully these will last for a few years with some regular cleaning. Good times.

Thanks for all the help, CSR!
 
I had the same pump height problem last year, it took a while to sort out. Frustating that something so simple became so hard. I ended up on ebay to find an new “old version” of the pump that fit in my assembly. It is so nice to shower on the boat tho, worth the hassel.
 
If you have wire connections inside the box, chances are the pump has been replaced before.

I see you all have different sized pumps. For reference, I have a Rule 1000 front, and a Rule 800 aft box. The idea of connecting the boxes makes sense, but I don't think I'd be putting smaller pumps inside.
 
What a classic boating project. An absolute classic.

So I shot out to the boat last night to replace the pumps and switches. An unusual Tuesday trip to the boat. I was actually looking forward to having some quiet time, drink a beer, work through a fairly straight forward project. Of course that was not what happaned.

First and foremost - my issue was 100% electrical. Once I removed both pumps from their baskets it became immediately apparent what the issue was. Both pumps were wired to the switches with hand-wound connections covered in electrical tape that were LEFT IN THE SUMP BOXES. Hilarious. I had a good laugh. Not so funny was that the aft connection was actually warm to the touch when I grabbed it. I'm not sure this would have ever caused a fire risk but it was unsettling.

So I proceeded to replace all the gear anyway. Why not, I'm already in there. And the existing wires were cut so short there was no saving this stuff at any rate. As I move forward it becomes clear that the new Rule pumps and switches are nowhere near the same size as the set that were in the boat. Much bigger, all around. So I had to do thirty minutes worth of finagling to get the first pump and switch in. No problem, works like a charm. Done and done.

I move on to the second pump, the sump with the 800 (I don't know why these would be different sizes). I do the same reconfiguration as the prior pump, get it all wired up, drop the pump in the basket and PRESTO - the fricken new 800 is a 1/2" taller than the 500, and a 1/2" taller than the 800 that I just pulled out. Good lord. Of course the top won't go back on the sump box with it like this.

And of course West Marine closed an hour ago.

I'm going to go grab another 500 today and swap out the 800. With any luck this should conclude this project. I'll have all of the new connections tied up, out of the way, out of the water. Hopefully these will last for a few years with some regular cleaning. Good times.

Thanks for all the help, CSR!


I'm sorry this is so funny - but only because we've all been there! From the,

I was actually looking forward to having some quiet time, drink a beer, work through a fairly straight forward project.

to the,

And of course West Marine closed an hour ago.
 
I'm sorry this is so funny - but only because we've all been there! From the,

I was actually looking forward to having some quiet time, drink a beer, work through a fairly straight forward project.

to the,

And of course West Marine closed an hour ago.

I thought this would be a relatable experience. ha. What a riot...
 
Hard to believe two pumps would go bad at the same time.
If all the connections are clean and tight, I would check to make sure the float switches are good before I replaced the pumps too.
Those sumps get pretty cruddy inside and those float switches don’t like crud.
I keep a spare aboard just in case one craps out.
Cleaning the sumps has become something I do a few times a season.
I’m also trying a few things this season to see if they stay cleaner.
1. Using A/C pan tabs in the pans to try to keep that stuff a bit cleaner.
2. No more bar soap on the boat. Replaced it with Body Wash to cut down on soap scum buildup.
3. Every week or so I put a teaspoon of Noflex Digestor (use it for the heads anyway) in the shower drains and flush it through with a big cup of hot water.
 
If you have wire connections inside the box, chances are the pump has been replaced before.

I see you all have different sized pumps. For reference, I have a Rule 1000 front, and a Rule 800 aft box. The idea of connecting the boxes makes sense, but I don't think I'd be putting smaller pumps inside.

Yes indeed. This was clearly a prior-owner project. The OEM connections were still intact outside each sump box. What happened inside the boxes was pure comedy.

For what it's worth the 500GPH is more than enough for my application. I believe the prior owner of my rig but the 800 in the forward sump to overcome a stuck back-flow preventer. I pulled it while replacing the pump (the first time) and was surprised it was left behind inside the tube that goes through the wall of the box. The new pumps have them integrated into the pump nipple, not external.

I finished this all up last night. Got a 500 put into the forward sump and she runs like a charm. I ran the shower full-stream and the 500 is able to empty the box at a rate that must be 10:1 compared to the shower output. I was originally worried about 800 vs 500 but I am no longer.

1000gph seems like it would be major overkill for the size of my sump??? I do like overkill but at that rate it would probably act like a stern thruster at the aft drain :)
 
FWIW, a 500 gph pump is 8.33 gpm; a 800 gph pump is 13.33 gpm; and a 1000 gph pump is 16.67 gpm.

I believe that most of our freshwater pumps are in the 3-5 gpm range.

You will be just fine.

Jaybeaux
 

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