2021 Vista Li-BIM install for Lithium Install

[AKaDougie]

Hello,

I had to replace my coach batteries so I got two Li batteries and didn’t notice that I could damage the alternator with current setup.

So I ordered an LiBIM and now I am confused on how to swap.

Do I just take the battery mode solenoid out and place the BIM? When I look at wire diagram
https://www.winnebago.com/Files/File.../000235251.pdf
And when I looked at it I have a few cables I’m not sure they are.

I tried to trace the wires in https://www.winnebago.com/Files/File.../000216816.pdf
And I think KKG is coach fuse, FM is for the switch, and LR is for ignition.

Am I correct in thinking I can just swap solenoid out for BIM and that will protect alternator?
So much information and every rig is different so I figured I ask for help.

[Morich]

I have limited info or ideas on the BIM switch but there are some things that I can discuss about the current wiring as one of my favs to talk about!

Some things to help? One is that Winnebago stamps ID on their smaller wires.


You can then go to this chart to "decode' that stamp and find the "from" and "to" of each wire. That often leads to a hint of what to expect from each wire for it's use!
In the OEM mode solenoid, the LR wire brings 12volts from the dash area down to the coil in the solenoid. this comes from two spots at front. One is when we push a momentary switch with various names like "boost or Aux". That is the switch used to "jump start" a weak chassis battery as the solenoid connects coach and chassis batteries together!
The second time LR gets 12 volts is when the RV engine is running, a point often called "ignition hot" also powers LR to operate the solenoid as we drive.
That lets us put some charge in the coach batteries as we drive.

When LR get 12volts, it goes to a small lug on the solenoid, through a coil inside and then to ground to make the solenoid operate!
There are two versions of this solenoid, 3 or 4 posts! When you have the 3 post type LR goes on the single small post, through the coil inside and then the body of the solenoid gets ground from the mounting screws! Those screws can be flaky , so many RV also have the wire FM which is ground.
On that design, the coil inside may be brought out as a second small lug and the FM is put there to provide ground.
If you have a 3 post, Wire FM is often just laid down on the mounting screw to make a more reliable ground !

So the solenoid wiring is small wire LR on one small lug. If you have a second small lug, wire FM goes there.
If a 3 post version, FM can be run to the mounting as a ground!
Then on left and right, there are two big lugs. Left is usually the big battery cable from the chassis side and right is the battery cable from the coach batteries!

ARGH!! I just flipped over to look at the drawing you linked and I've got to say it is about the worst I've seen for this section! Hard to read, so I understand any confusion you have!

Note the triangle with 6 in it? that points tot he notes at eh left side and it tells to lay FM on the screw!
The info above is correct as far as I know but it is not clear on that drawing, for sure!!!

I think you will be wanting to leave the coach battery disconnect the same and not involve it but only swap the solenoid.
The BIM does much the same thing but is a solid state item rather than the older electronic relay of the solenoid!
But I've not been involved in the switch to newer batteries so I will leave that for others who have been there! I think there may be other points to consider but not my area to say???

[creativepart]

Hi,
I made part of this change on my 2017 Adventurer about 2 years ago. In my install the OEM BIM is in between the chassis and house cutoff solenoids.

I did not go the LI-BIM route and instead went with a DC2DC charger and I disconnected the OEM BIM. But, it was obvious to me what would have been the wiring scheme had I used the LI-BIM.

The factory BIM was wired with main chassis and house connections and then each additional connection was clearly labeled. I looked at those and then looked at the LI-BIM and the connections were just about completely the same. So, while I didn't do it, it appeared to be a simple wire move from the factory BIM to the LI-BIM one wire at a time following all the labels on both devices.

Now, I don't know how different the BIM on a 2021 Vista is than my Adventurer, but I doubt it's all that much different.

Here's the labeling on my RV's BIM:

[Morich]

Looking at the two RV and this sections of wiring, I see some of the same but several points that make it more difficult to figure.
The vista has no cutoff relay for the chassis at this point which seems to make it look less confusing and difficult than the Adventurer!
But that, fake us out if not careful about the time and the way battery management was changing!

The Vista in question was not using the BIM but the older solenoid! That makes a change on the first being mostly a simple swap of BIMs.
The second with OEM solenoid doesn't have the same wiring as the BIM and that can throw in some more questions!
Part of it can be sorted by looking at what the wire ID chart shows a wire does and placing it to do the same on the new BIM. For instance Wire KKF does carry power to the chassis fuses and KKF does the same for coach fuses.
That just takes some study on where to pick those power sources and keep them fed the same way.
But then there are other small wire differences to figure. Things like where to get the SJ and LJ as used on the BIM if there are not the same wires on the solenoid?

DC-DC sounds right but that small wire question is not one I've done or even started to figure! I'm sure they are needed to make a good change to BIM but if they are not in the OEM wiring, where and how to get them??

Hope the directions for the BIM are more help? I try not to stick my foot in that deep pool without more info!

[AKaDougie]

My RV does not have a BIM currently.
Only the solenoid and coach relay disconnect, as far as I can tell.

[AKaDougie]

�� exactly

The more I see the more confused or second guess myself I get ��

I agree with you the FM is ground and LR is ignition.

So now I’m trying to figure out where the battery boost switch is and how that all works in my layout, or if I really need to route through new BIM.

[creativepart]

Bummer that your Vista has the non-BIM system. I'm pretty sure I've seen videos on YouTube showing the Li-BIM install on a non-BIM setup. I'll look and see.

Here's what I found NOTE, it's not likely that either of this address your situation directly. But "maybe" they'll help you figure out your setup:

https://www.youtube.com/watch?v=DEXJ3TgAM3g

https://www.youtube.com/watch?v=KF0uf0bv2fM

[AKaDougie]

Yes I have watched them all, sadly. Some help but not really my setup or situation.

On a different note though my converter is not for lithium, however, I still achieved 100 percent charge while on shore power with my refrigerator running in RV.

[Morich]

The battery boost, Aux, or other names for the same switch will be on the dash or near the driver as a way to let them hold a momentary switch to connect coach and chassis batteries together through the solenoid. It might be thought of as a "jump start" for a weak starting battery but done by the solenoid rather than getting out jumper cables!
That wire LR also gets 12Volts when the engine is running to connect the same!
After the 2010 year, they stopped online drawings for the 12volt, so I snipped from a 2009 to show what I was getting at above! Same parts but shown a different way that we can see better than the parts drawing that showed the shape more?
Click this snip to get better view!


Your year did not have the chassis battery disconnect, so ignore that part at left!
You have the chass. battery on the solenoid left big lug and coach battery on right. Maybe there is still tape makers wrapped on the big cables ends to ID them? What controls this solenoid is the blue marked wires from the dash area and ignition hot sending 12 volts to the coil of the solenoid and on to ground where wire FM is also bringing ground. Double grounded, just to make sure?
When the solenoid closes, the red and yellow are connected together for the jump start or as we drive!
That solenoid is what will be replaced by a BIM on later models, so most of the rest stays the same if you can figure how to get the wires moved over to the BIM!

But still some good things to know as this is a frequent problem and confusing.
See how coach battery has some that goes THROUGH the disconnect and some takes off to the fuses BEFORE the disconnect? Safety items like CO and propane detectors stay hot and can run the batteries down when we store, because they DO NOT get disconnected with the switch and relay!

The green line is hot if the disconnect relay is closed and feeds power to coach fuse panel and generator starter! The blue marked lines are the controls for the disconnect relay switch to open or close it!
Wire KKF takes much of the power to the coach batteries and KKG on the far left does the same for the chassis, so it may actually be connected in this area, so make sure not to drop iT!

See if that makes it better to look at. Sorry we did not find one that actually matches what you have with only the coach disconnect, but I can see how this works better than the picture type drawing for your RV!

Maybe I look at too many drawings? They tend to make sense, so maybe my mind is a bit screwed up?