Please help Identify

[ARMYGREEN]

What is this?

Fuse?

The wiring comes from the trailer into this black box then to the water pump.
Is it needed? Can it go faulty?

[dznf0g]

Is it mounted on the pump? I'd guess it's the module for variable speed operation.

[richard5933]

Might be a module to accommodate multiple on/off switches throughout the trailer. I've got something similar on my coach - each switch is a momentary switch and when any of them are pressed it cycles that little black box into on or off, depending on where it started.

[ARMYGREEN]

I do only have one switch.

It is mounted next to the pump.

[Rich W]

Originally Posted by richard5933

Might be a module to accommodate multiple on/off switches throughout the trailer. I've got something similar on my coach - each switch is a momentary switch and when any of them are pressed it cycles that little black box into on or off, depending on where it started.

I think this is the answer, even if there is only 1 switch. Google Water Pump Control Module you will get several hits for RV pumps. Reading the descriptions it looks like it allows thinner wire to be used (like a starter solenoid is my guess) in multiple locations. Probably a standard install as part of the wiring harness.

Designed To Operate As A "Low Side" Remote Switch In 12V DC Systems
Minimizes The Use Of Heavy Gauge Wire That Runs Throughout The Coach
Signaling From Multiple Points Along The Single Wire MONOPLEX Can Be Easily Accomplished With Inexpensive Switches, Providing Momentary Contact To Ground
Simplified Switches (Momentary Buttons) Increase Reliability
Negligible Standby Current Makes This System Superior To Conventional Multipoint Relay Switching
Labor And Initial Installation Costs Are Reduced Compared To Multipoint Switching Using Conventional Switching

[ARMYGREEN]

Any harm in bypassing it?

[richard5933]

Originally Posted by ARMYGREEN

Any harm in bypassing it?

Potentially, yes.

The pump itself draws a considerable amount of power, possibly 5-7 amps DC.

Aside from being able to add multiple switches, a water pump controller serves another important function. Rather than having the higher-capacity wiring running from the power source, through your switch(es), and then to your pump the controller shortens the run so that it essentially goes from the source directly to your pump.

By using the controller, you can have much lighter gauge wiring running from it to the switch(es), as well as being able to use a lighter capacity switch.

If you eliminate the controller you would be sending all the power to run the water pump through the switch and through a much longer stretch of wiring, adding voltage drop and possibly damaging the switch.

What would be the reason you'd remove it?

[ARMYGREEN]

OK. Here is my situation.

2016 23FB International, very little use prior to us getting it this year.
The water pump will not shut off as I posted in another thread.
I have gone through a bunch of trouble shoots and still have come up with nothing.
Does not appear any air in the system. Does not appear to have any leaks. Holds pressure around 58-60psi.

I took it to Airstream they looked at it and their thought was my pump might need to be adjusted or replaced.

The pump that was in it is a 4048-153-V75 4gpm which I can not find anything about. I find a 4048-153-E75 but am unsure if that is the same. I feel like it is original to the International as there are no other holes when I removed the water pump to inspect.

Airstream says they have never seen a 4gpm pump in one. They say it is large and pulls more power and would replace it with a 3gpm pump.

Soooooo

I bought a new pump 4008-101-A65 3gpm and put it in yesterday.
It runs up to the same pressure and also will not shut off.

So that takes me to this little box as I will call it. It seems to me the original wiring harness from the Airstream comes out (two wires) and goes into this box they are marked power. Then four wires come out of the box and go to the pump two marked pump and two marked pressure.

All others that I can find on the interwebs are just wired in without that box.

So I feel like all the power is going through the original two wires regardless of the box?
So is it needed?

The box appears to be melted a bit on the back side so it may be my problem?

I can't seem to find that part by the numbers on it.

[richard5933]

Does the new pump you installed have a built-in pressure switch to shut off the pump?

[ARMYGREEN]

Does anyone else have one mounted right next to your pump?

[ARMYGREEN]

Originally Posted by richard5933

Does the new pump you installed have a built-in pressure switch to shut off the pump?

The old one does and the new one does as well.

[richard5933]

Originally Posted by ARMYGREEN

The old one does and the new one does as well.

If the built-in pressure switch is working, and if the pump is reaching the set pressure, then the pump should be shutting off regardless of what else is attached to it.

The power to the pump motor should be going through the built-in pressure switch, which should be the final arbiter of whether or not the pump runs.

[ARMYGREEN]

I agree in theory.

So if I eliminate the box wiring. Power comes in from trailer to pressure switch, pressure switch to pump. Ground goes out of pump. When pressure is achieved pressure switch trips and shut power to pump.

With this black box as you can see in the pictures, power comes in from trailer to box, then box splits and power and ground go directly to pump and two wires go directly to pressure switch at the same time. So I am assuming that when pressure is achieved it send a message back to box to shut down pump which It might not be doing?

[Rich W]

Does this diagram help?
On second thought, you said there were 6 wires, right?

[Rich W]

https://www.amazon.com/Shurflo-40481.../dp/B007RYMT7O

I found another site that sells the E75 version.
https://www.adventurerv.net/shurflo-...mp-p-1733.html

Designed specifically for mid-sized RV’s. This microprocessor controlled variable speed pump silently delivers 4.0 GPM and pressure up to 50 psi for "Just Like Home" flow. Features 4 chambered high flow design, extra large valve passages, and variable speed/no cycling. Experience more enjoyable showers, impressive dual-fixture flow and ultra-quiet performance. 1 year warranty. 1/box. This item is discontinued. Once inventory is depleted you will be shipped the new replacement 4048-153-E75 pump.

[ARMYGREEN]

Yeah. 6 wires total. 2 wires in. 4 out.
I have found the E75 as well. The one that was in there was a V75. Might be the same I don’t know?
I talked to a buddy that is pretty electrical savvy and he thinks it is a pressure switch which makes no sense since the pump that was in there also had a pressure switch built in.
Anyway I pulled the black box out and wired it like it appears everybody else has their water pump wired and it worked perfectly now. So whatever that black box is was definitely the problem.

[Rich W]

Yeah, somethings up with the module. I would have done what you did. You can always splice wires again. I'm wondering why AS support wasn't able to help to at least identify the box.

Good new, glad you're up and running again.

[richard5933]

Do you have the factory wiring diagram for that pump and the controller setup?

Sounds from your description that someone wired the pressure switch to control the pump via that controller instead of directly on the pump.

On pump controllers that I've seen, the power coming from the trailer is fed to the controller. If the switch triggers the controller to turn on, it then sends the power to the pressure switch. If the set point has not yet been obtained the pressure switch will send power to the motor. If pressure is at the set point it does nothing.

You mentioned that there appears to be some funkiness about that controller, so I'm thinking that in addition to some odd wiring you've got a defective controller.

[Rich W]

Okay, I'm giving up on that black box/module/whatever. I can't find the part, an owner's manual, anything. You might find an address (email or snail mail) and contact Shurflo about it.

The description of the pump on their website that is similar to yours and includes a link to one we both found indicates that the module is to control the water flow by speeding up or slowing down the pump so that it runs quieter and provides more pressure when necessary. With no part number on it or parts listing it seems really silly because if the part fails you can't order another.

On my outboard there is something called a rev limiter to prevent you from over-revving the engine in neutral. It was larger but very similar in construction to the one on your pump. Mine went bad and started arcing to the engine block but only over a certain RPM, otherwise it was fine. It took me about 4 months of searching the Internet to finally diagnose it. Mercury has an online parts catalog by serial number and it was easy to get the replacement and install it; no more problem.

I wish you luck if you want to pursue it but buy a box of them if you find the part number, make a YouTube video and sell them at 3X the price you paid. Otherwise, just enjoy the pump noise.