Wiring a “Gulper” Cut-Off Switch – Lighted RV Switch Wiring

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Our Winnebago EKKO has a “Whale Gulper” pump to drain the bathroom sink and shower.  It mostly runs on autopilot, but there are times when the autopilot makes the wrong decision about running the (rather loud) pump, so we wanted a way to shut this off with a switch.

But we also wanted that switch to light up when the pump was off (to remind us to turn it back on!).  But a Switch OFF/Light ON configuration requires a special kind of switch.  I show you what it is and how to install it in this video.

But this kind of switch could also come in handy in other situations, I explain that up front.  Have a watch:


I explain it pretty well in the video, but the switch I used here has a few key characteristics:

  • SPDT (Single pole, double throw), which means there’s one circuit that can be switched two different ways.
  • ON-ON, which means the switch is on either one way or the other.
  • NOT “ON-OFF-ON”  That would mean there was a center “off” position where neither path was energized.  We don’t want that.
  • NOT “ON-(ON)”.  The () would indicate a “momentary” switch, where the current path is connected only while you hold down the button.
  • Rated for 12 volts, 20 Amps, continuous duty.  That’s more than enough for the pump I wanted to switch.
  • Has an independent light circuit.  This means you can control the light independently of the switch position.


Materials List

The switch I wound up using was the V4D1-A60B from Carling industries.  I bought it from New Wire Marine.  (We have no affiliation with them at all.  They just had the switch in stock.)

But New Wire Marine sells the switch body bare.  I had to buy a cover plate for it to complete the switch.  I chose the “Bilge” lighted cover, which I also got from New Wire Marine.  (But they do have “custom cover” options – fun!)

I also got a mounting trim ring that just snapped into the bathroom cabinet without needing any screws or fasteners.  This is the one I purchased.

The fuse holder you see me installing is this one:  The Littelfuse 0FHA0030XP ACS ATO HD Carded Inline Fuse Holder.

I am using WAGO connectors to make the connections under the seat.  I think they’re super handy, and I’ve never had a failure related to one yet.  I use some 2-conductor connectors, and one 3-conductor connector.

I’ve really started to like this wire I’m using.  It’s this stuff, which I just got from Amazon.  It’s 14 gauge, so it can handle 15 amps.  It comes in various colors, which make identifying wires in the bundle easier.  The copper strands themselves are tinned to help resist corrosion.  But most importantly, the silicone insulation on the wire is super flexible.  It makes it very easy to work with and it will bend and move wherever you want it.

If you’re looking for some super-flexible wire loom to go with the super-flexible wires, you could try this Alex Tech Cord Protector.  The only bad thing I can think to say about it is that you have to singe the ends of the tubing where you cut it so that it doesn’t unravel.

Finally, the wire strippers that you see that sometimes work fantastically and sometimes just try to frustrate me are these Irwin wire strippers.  They work great on the silicone insulation, but struggle with firmer insulation.  I suppose this just means they’re out of adjustment somehow, and I should just figure out how to adjust them.


As I mentioned in the video, this “warning light” function isn’t the only time knowing a switch like this would come in handy.  It would also make a perfect night-light or locator switch in your RV.

Anyways, the rest of the information you need to get this working is in the video.  If you have comments or questions, sound off below and I’ll try to answer them for you.



James is a former rocket scientist, a USA Cycling coach, and lifelong fitness buff. When he's not driving the RV, or modifying the RV (or - that one time - doing both at once), you can find him racing bicycles, or building furniture, or making music. In his spare time, he works for a large IT company.

    21 thoughts on “Wiring a “Gulper” Cut-Off Switch – Lighted RV Switch Wiring

    1. Mamacast

      James, still waiting for recalls on the EKKO to clear but how would you route the wires from the gulper location in 23’s?

      1. James - Post author

        Good question, but I think the answer is the same.
        Working backwards, I’d run the wires the same way into the compartment under the seats.
        From there, there should be a hole in the floor down to the compartment below. Use that to get to the Gulper.
        Other than that, the process should be the same.

    2. Randall Stonesifer

      I have been thinking I would eventually add a gulper switch to avoid the issue of it not shutting off some inconvenient time. I am glad I waited to see your idea! All installed except I did not have a 10 amp fuse in my box.

        1. James - Post author

          Well, as for the “house”, you could just turn the batteries off (on the batteries themselves). If somebody didn’t already have an EKKO, it would take them a long time to figure that one out. You can’t see that the batteries have a switch from the outside – you just have to know.
          If you’re talking about the vehicle, there are vehicle security options out there already – alarms with the capability to disable, etc. Viper. Compustar. Choose whatever your installer will work with.

    3. Joe McGuire

      Looks like Winnebago learned from the Boldt BL. They installed a Shurflo 4008 diaphragm pump on the Boldt BL shower drain, and the stock setup had 2 different screens that would often clog in about half a shower. I’m guessing they switched to this pump as it appears to handle debris a lot better. I’d built a new screen drain that had like 10x the surface area and I could clean without disassembling, but next go around I’ll have to look at one of these Gulper pumps. Curious if it’s bullet proof with hair, as that seems like it could still clog up a diaphragm based pump.

      1. James - Post author

        Supposedly, the gulper pumps are fine with hair. Ours has never clogged since its install. I do have to clean the strainer in the shower occasionally, but that’s it.

    4. Don Kane

      I have been happy with with this elegant little lite-however-you-want N/O or N/C round push switch (below) It’s rated at 10 Amps/12V (not sure if there is 15A one for this series). I have used it for our water pump, the solenoid to open the propane, the switch for the WeBoost (which, if you leave it on, uses an insane amount of power in my opinion), and various silly lights in service cabinets. If you wire it into the positive side of your stuff (that is, between your fuse and your stuff), you only need to find a local ground to power the light, and then you don’t need another fuse. It is nice for mounting cuz you just drill and go, but you do need access to the back of the switch so you can screw on the retainer nut.


      1. James - Post author

        I used something similar in our last RV for a water pump switch. I thought about it here, but didn’t go that way for a couple reasons.
        First – I couldn’t find a 15 Amp version. Maybe I was just being lazy…
        Second – I had originally intended to install this switch in the wall inside our bathroom where I relocated a light switch. That wall is only 3/4″ deep, and I wouldn’t have been able to get access to the inside to install the switch.
        When I finally decided to install it in the bathroom vanity, I had already purchased the switch I used.
        Third? Does that switch do the swith-on/light-off thing? The ones I used in the past were all “switch-on/light-on” only.

      2. Don Kane

        Your switch also seems to match the switch next to it.

        Pretty sure the switch I posted is N/O and N/C; the light can be wired on when on, on when off, always on and of course always off.

    5. Pete Schoenenberger

      Very informative video regarding the switch installation. We just spent a week in our Ekko and didn’t experience the issues with the gulper but I like the idea of turning it off when I want too. Does the noise from the gulper get magnified through the shower drain? It seems that it would, any experience with that?

      On another note I noticed the door to the cassette and it looks like you have the SOG installed. If so, how do you like it?


      1. James - Post author

        Yeah, you hear the noise through both the sink and shower drains.
        We do have a SOG installed. It’s… OK.
        I’m trying to work out something else, so I’m still tinkering with it.

    6. karl stock


      Could you not have changed the taps used to ones fitted with micro switches or just added micro switches to your existing taps?.to start pump when used ??

      I’m not saying you method is wrong just still not automatic.

      Best Regards


      1. James - Post author

        I suppose I could have done that, but it would have been either more difficult, or more expensive, or both. Micro switches would probably have been rated for fewer amps – which would have meant installing a relay or something. That’s not bad, but it’s more than most casual RV modders would likely attempt.

        Plus… That gulper pump also has a feature where it keeps running for about 6 seconds or so after it stops detecting water. It does this to clear the lines of any remaining water. Switches at the tap would cut the power to the pump when you turned the water off – defeating this feature.

        Plus plus… there are two fixtures that drain to that location. It would have required two sets of tap/switches wired in to logically power the pump if either was turned on.

      1. James - Post author

        That would work… until you wanted to use the water while the RV was tilted.

        Every automated solution I thought of, I came up with a reasonable exception.
        In the end, I thought putting a human in the loop was the best solution.


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