Fix for Connext Battery Voltage Issue - Confirmed

[Mainah]

I have checked my boat and now see the small bundled wire which was hidden very well in the factory harness on my boat. Obviously less work to just use that but it swaps which is which on the display. In using that option the pins could be swapped at the spu connector to make it read the correct batteries on the display as the connector does come apart. This is yet another one of those many ways to skin a cat things. This begs the question even more; why was it so hard for the engineer/ factory to get this right?

 

[AJack]

I looked at my switches today and saw a “Start” wire, is the “Aux” wire in this same bundle?

 

[Pullen724]

@Mainah - I havent tried to pull apart my connector at tue SPU yet - you mention the pins/wires could be swapped to correctly display battery on connext screen. Are the pins easy to pull out and put back in? Do they reinsert back in tight or is there a chance of breaking whatever they catch into on the connector?

Also, if just cutting the sense wire near battery switches and connecting straight to the start battery +, is there any need for a fuse there?

 

[Mainah]

@Mainah - I havent tried to pull apart my connector at tue SPU yet - you mention the pins/wires could be swapped to correctly display battery on connext screen. Are the pins easy to pull out and put back in? Do they reinsert back in tight or is there a chance of breaking whatever they catch into on the connector?

Also, if just cutting the sense wire near battery switches and connecting straight to the start battery +, is there any need for a fuse there?

It has been a while since I looked at the connector not sure I recall the details of it. I did use fuses because I am me but in truth not needed if the wire is of sufficient gauge. I use 14 awg true marine wire for lots of stuff due to its casing being much more robust than 16awg.

 

[JDRacing]

Did mine today. Based on the pictures posted, it looks like no two boats have the looms running the same way. I'd expect my 2018 212X to look like Jameson's 2017, but they are run differently. Fortunately they all seem to work the same way. My "Aux Batt" wire was bundled with a bunch of battery/red 12-16 guage (or so) wires, terminating in a much larger (like 4--6 gauge) red wire that went to the House switch. None of that appeared to be fused near the battery.

But I followed the protocol, and even bought some 1/4" split loom to run the wire inside of on the way to the starter battery. Worked great. As others have noted, "Aux" on Connext is the starter battery, and "Sys" is the house battery.

Thanks to all who contributed to this fix

Jeff

 

[Pullen724]

Update on my end - I have a 2016 242 Limted s

The sense wire was located in the bundle near the battery switches. I cut and ran over to the other battery and it worked as described previously. Now, with my OCDism.... I did not want the readings to be switched on the connext screen so I switched the connectors in the SPU plug (which took 2 minutes) andnow the correct individual reading is on the correct battery as shown on the screen. I wish I would have done this a long time ago but was hesitant to cut into wiring.

For those hesistant like I was, this really is a simple fix. Only new wire needed is a connector wire from the sense wire near battery switches to the positive terminal on battery (about 8”).

Thank you to all who provided updates on this mod!

 

[AmesJainchill]

Just finished reading this entire thread. Very informative. Thanks everyone! I will be reviewing how the 2019 242 LSE is set up with my dealer well before I pick it up this spring. Just bought it a couple weeks ago and they would be doing a head install and various prep over the winter, so plenty of time for me to go over this with them and make sure the latest 12" connext reads correctly.

 

[Mainah]

Update on my end - I have a 2016 242 Limted s

The sense wire was located in the bundle near the battery switches. I cut and ran over to the other battery and it worked as described previously. Now, with my OCDism.... I did not want the readings to be switched on the connext screen so I switched the connectors in the SPU plug (which took 2 minutes) andnow the correct individual reading is on the correct battery as shown on the screen. I wish I would have done this a long time ago but was hesitant to cut into wiring.

For those hesistant like I was, this really is a simple fix. Only new wire needed is a connector wire from the sense wire near battery switches to the positive terminal on battery (about 8”).

Thank you to all who provided updates on this mod!

This is likely the best way to do it. I will try editing the first post to reference this.

My only added thought is that I don’t think the factory run to the spu is dedicated for at least on of the sense wires. This could lead to volatge drop when other items are drawing from the same main the branch is connected to. Not a big deal but something to be aware of. With dedicated runs there will still be voltage drop when high amp items are drawing power like amps, blowers, ballast pumps etc. I personally notice voltage drop on my house battery with the engines off and playing bass heavy music at high volume or with all 3 of my ballast pumps running at the same time. I added dedicated runs to the spu from each battery.

 

[JDRacing]

As noted a few posts above, I completed this fix a few months back, although I had not switched the leads at the SPU, so "SYS" read the house battery voltage and "AUX" read the start battery voltage. Inspired by @Pullen724's post and @Mainah's comment above, I just now switched the leads so the SYS and AUX voltage readouts are consistent with how the owner's manual says they should be.

The little tab which releases the wires from the plug works just as @Mainah described in post 5 and the accompanying picture. Just push it in with your fingernail and on the opposite side of the plug there are two smaller tabs which pop up, indicating the wires are able to be pulled out. No tools necessary. It does take a bit of a pull to get the wires out of their sockets after the tab is released---which is actually a good thing. My biggest concern in doing this was that, when I pushed the tab, 15 wires would come flying out of their sockets, and I wouldn't have a clue how to put it back together. Don't be afraid to give each wire a decent tug to get it out of the socket once the tab is pushed. And remember, if you hooked up the "Aux Batt" wire straight to the battery as described above, it's hot when you pull it out of the plug, so don't let it touch anything, or disconnect it at the battery first. The "Sys Batt" wire should not be hot if the battery switches are off.

@Mainah, this is a fantastic fix to (yet) another wiring design error Yamaha built into these boats. Because of your efforts, it can now be repaired with about 1/2 hour's work and a bit of wire scrap so it operates the way the factory clearly intended, based on the owner's manual. Thank you for figuring it all out and sharing it.

Jeff

 

[Cambo]

Just did this as well great info

Swapped the pins in the SPU its located under the starboard seat its the plug on the left the wires are hard to see labeling aux batt and sys batt they were in the middle row. The grey large tab needed a push with a small screwdriver pulled the two pins out and swapped them.

Then clipped the wire by the battery switch labeled start aux crimped on a fuse holder and terminal attached to the start battery.

It’s done in the order above because the wire will be powered once hooked to the start battery

Tested and it works correctly now when you hit the start you can watch the voltage drop on the sys battery voltage reading . Now if I decide to run the stereo I can see that my starter battery has the correct voltage and know that it will have plenty of power to start the motors. This can also eliminate the issue of accidentally combining the batteries running the stereo and draining all the batteries. Anyone with a multi amp system should absolutely do this it’s very easy . Honestly Yamaha should really offer a recall to fix this issue after doing it once it would take about 10 minutes to do it again.

The Aux gauge is just slightly off in calibration or voltage drop approximately .6 volts. I print and laminate a chart showing the state of charge

RV Tech Library - Battery Charge Voltage

 

[mark_m]

@Sweinberger let’s look at your setup in context. @Pinhacker71

 

[Nfinlay1]

Take a look at my photos 2 posts above yours. On the '17 there is a red sense wire that heads out of the battery area bundled with the main House feed. That red sense wire goes into the battery switch cluster and is connected to the House battery switch (you have to remove the switch cluster to see the connection bolts on the back of it).

You need to remove that sense wire from the House battery switch and instead connect to the Start battery switch. After you do this the Connext will read the House battery as "System" and the Start battery as "Aux" separately.

What you are fixing is that as-is the Connext is getting its voltage reading from itself which is fed by the House battery named "System" on the connext. Also it is getting the "Aux" voltage from the sense wire, problem is the sense wire is also connected to the House battery. So both are reading the House battery. Which is why you need to swap the sense wire over to the Start battery switch.

If that doesn't make sense let me know and I or some else that has done this can go into greater detail.

I am going to probably as a really dumb question but I am new to this...Should I disconnect the negative leads to the batteries before doing any of this? I’m assuming yes...

 

[JDRacing]

I am going to probably as a really dumb question but I am new to this...Should I disconnect the negative leads to the batteries before doing any of this? I’m assuming yes...

It certainly couldn't hurt to do so. I pulled both the positive and negative leads off as I was doing this. And there are no dumb questions here.

Jeff

 

[Nfinlay1]

It certainly couldn't hurt to do so. I pulled both the positive and negative leads off as I was doing this. And there are no dumb questions here.

Jeff

Thanks! I’m not a huge fan of electricity so I figured it couldn’t hurt. I’m gonna go over to the boat this afternoon and look into removing the House switch housing and moving the sense line over to the Starter switch.

Sounds like something i can handle. ?

 

[JDRacing]

If you read the first of my two posts above, you will see that you probably do not have to pull the house switch apart to get to the sensor wire. In my boat was in a loom of other wires just past the switch (on the boat side, not the battery side, of the switch) and just involved pulling it out of a split loom, removing some tape, cutting the wire, splicing a new piece in and hooking it up to the correct battery. Pretty simple.

Jeff

 

[Nfinlay1]

If you read the first of my two posts above, you will see that you probably do not have to pull the house switch apart to get to the sensor wire. In my boat was in a loom of other wires just past (on the boat side, not the battery side, of the switch) and just involved pulling it out of a split loom, removing some tape, cutting the wire, splicing a new piece in and hooking it up to the correct battery. Pretty simple.

Jeff

I don’t think I am prepared to cut and splice anything on my boat, that kinda scares me. I think I’d feel more comfortable with just moving the wires between switches.

 

[JDRacing]

Yeah, I get it. Please let us know how it turns out. Hopefully your wires are all separate, unlike mine, where the loom of labeled wires terminated directly into a.much larger wire which went into the house switch. In other words, mine did not have a small labeled wire to move from one switch to the other.

 

[Nfinlay1]

Yeah, I get it. Please let us know how it turns out. Hopefully your wires are all separate, unlike mine, where the loom of labeled wires terminated directly into a.much larger wire which went into the house switch. In other words, mine did not have a small labeled wire to move from one switch to the other.

I have a 2017 so I am hoping it’s setup just like Asok mentioned. Heading over in about 20 minutes. Will report back then.

 

[Nfinlay1]

So while looking at the sensor wire I noticed a disconnected cord just hanging out...it looks like it comes from the stern of the boat. Should like be connected to the negative of the House battery?

Edit: I connected it to the Start battery negative post. I have no clue what it does...everything was the same when I turned the batteries on...looking at some other posts it looks like an extra loom of wires that other people don’t have.

 

[Nfinlay1]

Yeah, I get it. Please let us know how it turns out. Hopefully your wires are all separate, unlike mine, where the loom of labeled wires terminated directly into a.much larger wire which went into the house switch. In other words, mine did not have a small labeled wire to move from one switch to the other.

And it looks like my boat is setup just like yours. The Aux Bat cable runs from the Aux battery, towards the house switch then jumps to another loom that goes back into the engine bay. It looks like it skips the house switch all together.

Edit: Maybe it’s not setup like yours if it’s completely skipping the house switch. But if that’s the case, where the heck is it going??