Manual bilge pump button for MSX without Bilge button

[K447]

The MSX models do not have a bilge pump in stock configuration, and there is no Blige button on the handlebar.

This modification was originally conjured up for Keddano's MSXtreme, which is based on an MSX 150 hull with carbureted 1200 engine and CDI type electrical box. I think the modification can be applied to not only the stock MSX 140, but could be adapted for MSX 110 and MSX 150. The Weber engined models use a very different wiring harness than the MSX 140, but you can figure it out

The key is that the MSX does have a blue button on the handlebar, but Polaris has it directly connected to the NGI display, where it changes the mode of the display. Each tap of the Mode button switches the display to the next mode.

By using a diode to link the Mode button directly to the bilge pump power feed (Orange wire in Polaris wiring diagrams), pressing and holding the Mode button now sends power to the bilge pump. The button still cycles through the display modes, but now the bilge pump will also get power for a split second with each button tap.

Holding the blue Mode button down will now continuously power the bilge pump, just like the blue Bilge button on the non-MSX 1997-2004 models.

There are several stages to this project;

• Physically mount the bilge pump in the MSX hull
• Assemble the diode isolation jumper
• Modify the stock wiring harness to link the Mode button signal back to the electrical box
• Connect the wires

Diode jumper


Any diode of at least 3 Amps and 50 volts or higher rating should work. I would have preferred a 5 Amp or better diode, but this is all Radio Shack had in stock.


Crimp male and female spade connectors to the diode leads. Use heat shrink tube to insulate.
Note the orientation of the band end marking on the diode. Do not get this reversed.


Now we crimp a mating female connector onto the extended harness wire from the Mode button.


Another heat shrink tube seals it all together. Label markings makes it easier to remember what is inside.


Diode isolated feed from Mode button (which is now also going to be the Bilge button) connects to the Orange terminals, right where the Orange feed from the LR module connects. The actual bilge pump wire (Orange/Black) connects to the other end of the 3 Amp fuse, all by itself.

[K447]

Modifying the wire harness; stealing a wire to extend the Mode button signal back to the electrical box.

Since the MSXtreme does not have a fuel injected engine, it does not utilize the ESP feature. ESP uses switches on the steering base to detect when the handlebars are turned hard left or right, and momentarily increases engine power under certain conditions.

I removed the ESP switch mounting hardware, pulled the two Purple/White wires out of the harness, and reused one of the Purple/White wires which already ran back to the electrical box. The other two wire ends were capped off with heat shrink tubing and tucked into the wire harness sleeving.


The actual wire from the Mode button is Orange/Black. The weatherpack connector pigtail is spliced and soldered into the Orange/Black wire and taped/sealed.


The weather-pack 2-pin connector was retained so the modified wiring could be unplugged, if necessary. Only one pin in the connector is actually used.


The MSX has a pair of connectors near the hood hinge that extend up to the display itself on the hood.


Wires are labelled and then tucked into the plastic sleeving.

[K447]

If you have a stock MSX 140 and want to retain the ESP feature, simply thread a new wire through the wire harness sleeving from the splice location near the hood hinge back to the bilge pump feed.

Of course, the stock MSX 140 does not have an electrical box, so the wiring must all be done using weather sealed connectors and waterproof splices.

[Keddano]

Keith did a awesome job of installing the wiring to a well needed addition to my ski. Thank you K447 for all the help you provided at the gathering.

[K447]

Keith did a awesome job of installing the wiring to a well needed addition to my ski. Thank you K447 for all the help you provided at the gathering.

You got that machine running yet?

I expect the bilge pump button works just fine for you, now that you have hooked up the engine ground

[Keddano]

LOL, Little delay. Final part should be coming

[Mr. GP1800]

So looking at doing this to my MSX, in a nutshell, when you press the mode button it feeds battery voltage back to the display on the orange/black wire. The display seeing this voltage is what makes it switch modes. Doing this jumper, we are now forcing this power back to the orange that feeds the bilge pump, correct?

[K447]

So looking at doing this to my MSX, in a nutshell, when you press the Mode button it feeds battery voltage back to the display on the orange/black wire. The display seeing this voltage is what makes it switch modes. Doing this jumper, we are now [also] forcing this power back to the orange that feeds the bilge pump, correct?

Precisely!

The diode is needed so that when the bilge pump is powered from the LR module the bilge pump voltage does not back feed into the display's mode input.

With the diode in place the Mode button will work the display normally regardless of whether the bilge pump is currently being powered by the LR module (or even a separate toggle switch).

[Mr. GP1800]

I also discovered that when pressing the mode button and holding it, it does not toggle the display. The display only toggles when you press and immediately release the button.

[K447]

I also discovered that when pressing the mode button and holding it, it does not toggle the display. The display only toggles when you press and immediately release the button.

[Mr. GP1800]

Here is all of the wiring installed in my MSX 140. This was really a lot of messing around. I had to splice into the yellow wire in the main harness to tap for the signal to the LR-52. I also had to tap into the orange/black near the 2 connectors that go up to the gauge under the hood. I then ran an orange wire back off this splice, and inside the main harness I installed the diode. There is an orange and a yellow wire exiting the harness near where the LR-52 is mounted in the foam.



I did this all with weather pack connectors, so it can all be removed and the only non stock parts in the boat will be the capped off plugs on the yellow and orange wires exiting the harness near the battery. This will allow me to power a bilge pump and in my case a depth finder, and be able to use the blue mode button to control them with the engine off. You can see the empty 2 pin plug near the battery. I then made this little harness for my bilge pump and depth finder connection. There is an inline fuse holder for a 3 amp blade style fuse for the bilge pump.



For anyone wanting to do this, I did have a fair amount of time invested in this project. Fishing wires through the harness is not easy, and making good splices takes attention to detail. My splices were all soldered and protected with heat shrink tubing.

[K447]

Good wire harness work does take time, not only to make it look good but be reliable over time.

When I do one-off harnesses and such I sometimes label all the connectors and major sections. Mostly so I don't need to reply upon my own memory for how the thing works!

Yours looks looks nicely done!

[smokeysevin]

Bryan, can you upload a picture of the connector on the back of the gauge where the wire comes in? I may know where to get them so you wouldnt need to splice.

Sean

[Mr. GP1800]

I think they are just weather pack connectors. There are a pair of 6 pin plugs near the hood hinge

[smokeysevin]

Oh okay.

Sean