Wire Routing in 2022 320S Boondock

CatDaddy

I'm finding lots of great information about wiring diagrams on this forum.  Thanks to everyone that contributed!

I'm in the process of switching from two 6V lead-acid deep-cycle batteries in the tub to a single Renogy Core Mini lithium 300Ah battery mounted just forward of the Max8 air conditioner just behind the right wheel.  I will provide some photos here in case anybody else wants to see what I did.

I have the battery mounted, so the wiring games can begin, but I'm having trouble tracing where the wires are routed. I see a bunch of wires that disappear into the frame on the left side next to the junction box near the A-frame.  Where do they emerge? 

There are also a bunch of wires that go from the left wheel-well under the shower. I see a plastic wiring chase but I don't know where the other end is. Is it under the Alde system in behind the toilet?

For a bunch of reasons, I would like to keep the battery disconnect in the tub. I realize this isn't optimal from a wiring loss perspective, but that's what I plan to do. It keeps the disconnect accessible for the storage people.

As part of this upgrade, I plan to add a second solar panel (120W Renogy Shadow Flux) mounted on the rack and a second MPPT controller mounted near the battery. It looks like I can fish the wires from the solar panel under the rear plastic cowling through the hole for the license plate lamp wiring. Has anybody tried this? Is it as easy as removing the rear bars and the plastic cowling?

Some of the wiring diagrams I've found show a second disconnect switch between the WCFO and the battery. What is the purpose of this switch? 

How does one connect a battery maintainer once the batteries are removed from the tub? 

I'm open to advice. I am an electrical engineer with 40 years of hardware design experience, some of it in the solar industry, so I know the principles well but I don't know much about RVs. 

Here are the photos of my Renogy Core Mini 300Ah battery installed next to the AC unit:

I had to cut part of the gland to get the battery in. I used the "bigger the glob, the better the job" approach to sealing the gland. I don't know what the red, white and blue wires that go into the gland are for. I mounted two 1" strap loops to the existing metal frame for the AC unit and put angle aluminum around the base of the battery. Two Monster Lithium battery straps hold the battery in place, but I think one would have been sufficient. 

I also took about 4 feet of wire off the AC power cord for the AC unit. Not sure why NuCamp left it so long. It's enough of a mess without additional wire length. 

I plan to mount a Victron 75/15 MPPT controller just forward of the negative battery terminal on the back of the rear bench. I will probably mount the bus bars in there as well if I can make them fit, otherwise they will be placed in the left wheel-well. I will likely leave the existing Victron 75/10 MPPT controller where it is now in the left wheel-well.   I am also adding a 300A Victron Smart Shunt with temperature sensor. 

Yoshi_TAB

Hi, When I had my '21 320, I moved my batteries inside  (same location as you)  and a second inside solar controller  without cutting any holes in the Tab or fishing wires from inside to outside. All wiring was done inside .  Below is a wiring diagram of how it's done.  The top part shows the existing wiring.  The #6 wire from behind the WFCO is the same wire the runs outside , first to the the trailer junction box, then to the battery switch and then  to the battery.

So you can use this very wire, to the battery inside by splicing into it (X on a diagram).

I cut the #6 wire  from behind the WFCO and  ran it to a bus bar inside (via a switch).  Now you have the same battery wire (from the WFCO)  that went  outside  to the battery.  From the busbar, you can run it to  your inside new battery (do need a switch).  

But, an important thing to note is the power for the electrical emergency brakes comes from the outside junction box.  So this still needs to be powered.  To do this, I connected the downsteam #6 wire (where it was cut behind the WFCO and runs outside) , also to the bus bar.  This will then  provide power to the trailer junction box (provided the inside switch is on). I added a small indicator light so I can alway see the trailer brakes had power.  

I added a new switch inside in order to turn power from the battery OFF/ON like the outside switch since the outside switch no longer is connected to the battery.  But the outside switch will have power (via busbar) if you want to use it for something, but  I used it for an external solar  panel plug.


I added a second solar controller by using the existing wire (now unused)  that ran to the battery/switch outside.  I put a solar connector on the front tub, but put the solar controller inside near the battery.  The ground wire also runs outside so, you can just connect the inside ground to the OEM/existing ground bus bar.  It might be full, I blieve I added a second connecting ground bus bar (I also added an inverter at the same time as all this upgrade).


Not sure what yo mean by battery maintainer.  If you mean an external charger.  This can also be done inside by wiring it to the positive busbar, which goes to the battery.  To power the external charger, in my case (Victron IP 22) , I added a new outlet that I could turn off via breaker.  The last breaker (usually for the microwave) in the WFCO is a tandem breaker taking up two places.  You can split that into two slim  breakers (WFCO allows this) and create a breaker for another circuit for a stand alone plug to power a stand alone  battery charger inside.  

Hope this helps..ask any further questions.  I took a very deep dive into my 320 electrical when I had it.

Below is also my final wiring diagram that shows everything, although it added more components (inverter and transfer switch) than you plan to...but it may be helpful.

donmontalvo

CatDaddy said:

…[snip]…

As part of this upgrade, I plan to add a second solar panel (120W Renogy Shadow Flux) mounted on the rack and a second MPPT controller mounted near the battery.

…[snip]…

I also took about 4 feet of wire off the AC power cord for the AC unit. Not sure why NuCamp left it so long. It's enough of a mess without additional wire length. 

…[snip]…

I mounted a flexible 100W panel to my rack. Fits perfectly. I wrap the MC4>SAE cable around the aluminum bracket, and through the opening at the bottom of the Nautilus compartment.

I also shortened the AC wire on both the Air8 and Alde, and put right angle Leviton 20 Amp plug end, eliminated having to press in the original ones that loosen from vibration, due to all the excess wire.

https://a.co/d/9Zi1cZ1



My 2024 T@B 320S BBC is on the left.

CatDaddy

donmontalvo said:

I mounted a flexible 100W panel to my rack. Fits perfectly. I wrap the MC4>SAE cable around the aluminum bracket, and through the opening at the bottom of the Nautilus compartment.

I also shortened the AC wire on both the Air8 and Alde, and put right angle Leviton 20 Amp plug end, eliminated having to press in the original ones that loosen from vibration, due to all the excess wire.

The original owner of my 320S BD also ran the wiring for the extra solar panel in through the drain in the Nautilus compartment. I guess that is okay, but he used what is essentially lamp cord to wire in the panel. It was not rated for outdoor use and the UV rays had destroyed the insulation in just two years. It was kinda dangerous. I hope to bring the wires in behind the solar panel and through the license plate opening. 

I haven't had any issues with the AC or Alde coming unplugged, yet, but I will have a look at the power cord for the Alde. If I can shorten it, I will. Thanks for the suggestion!

CatDaddy

Yoshi_TAB said:

I cut the #6 wire  from behind the WFCO and  ran it to a bus bar inside (via a switch).  Now you have the same battery wire (from the WFCO)  that went  outside  to the battery.  From the busbar, you can run it to  your inside new battery (do need a switch).  

But, an important thing to note is the power for the electrical emergency brakes comes from the outside junction box.  So this still needs to be powered.  To do this, I connected the downsteam #6 wire (where it was cut behind the WFCO and runs outside) , also to the bus bar.  This will then  provide power to the trailer junction box (provided the inside switch is on). I added a small indicator light so I can alway see the trailer brakes had power.  

I added a new switch inside in order to turn power from the battery OFF/ON like the outside switch since the outside switch no longer is connected to the battery.  But the outside switch will have power (via busbar) if you want to use it for something, but  I used it for an external solar  panel plug.

I'm not finding the #6 AWG wire that you describe. I will look again tomorrow. In any case, I very specifically want to keep and use the disconnect in the front tub. I store my trailer at a storage place that needs to access the battery disconnect. For that reason I was trying to figure out how to fish a couple of heavy wires from the right-rear compartment where the AC unit is to the tub. I see wires going into the left (driver's side) frame, but I can't find where they emerge. 

Your diagram only shows one wire. Am I to assume that the return path is through the metal frame? Yikes!

The storage facility has provisions to connect a battery maintainer to the battery. I just don't know how people are doing that. I'm currently planning to provide an SAE connector, maybe in the Nautilus compartment to connect the battery maintainer, but I'm open to other ideas. 

I'm aware of the issue with the battery disconnect disconnecting power to the electric brakes. That seems like a terrible idea. I'm surprised that the regulatory people allow that. If I can eliminate that issue with this mod, I will. 

Right now, my main problem is finding a way to get heavy wires from the right-rear compartment to the disconnect up front. 

pthomas745

There have been owners who dropped the coroplast cover under the trailer and went into the battery area through the floor. 

Yoshi_TAB

Hi,

1.  Here is a link of someone who cut a hole in their TAB to route a heavy gauge wire.  Go to the last part of the post.  Although  I did not do it that way, I asked a bunch of questions and was provided very good details and photo of how they did it.

Renogy 2000W Inverter Install in T@B 320S - Page 3

2.  Front batterty switch Power.  If you connect the wire back to the junction box for the electric brakes, the front switch will have power, as the the switch wire runs through the trailer junction box. Here is a link to  diagram from the owners section here for a 2017, but my '21 was wired the same way.  You can see how it goes

5nxe0b15ew2c.jpg (800×626)


3.  Re" #6 Wire; It will be the fuse labeled converter power.  Mine was in the 6th slot..I think most of them are the same.  This is the wire that goes to the battery .




4.  Re: emergency brake and ON/OFF switch.  Totally agree.  A system safety device should never go through a switch the relies on a human to keep on. In the world of hazard analysis failure scenarios, that would not be acceptable.   When I did my electrical upgrade, I actually ran the wire directly and not through the switch to by pass having the need to have the switch on (the busbar is always hot from the batteries.  The new ON/OFF switch turns power off to the WFCO.  The small indicator light is a visual to say the brakes always have power.

5: I'm not sure what "one wire: you are referring to.  My diagram does not include any of  the OEM ground wires only the new ones i installed for the inverter circuit and solar.

CatDaddy

pthomas745 said:

There have been owners who dropped the coroplast cover under the trailer and went into the battery area through the floor. 

It's it difficult to drop the coroplast cover? 

pthomas745

Depending on the year, not too hard.  The newer trailers seem to have a more "solid" coroplast (or some sort of panel) under the trailer.  The coroplast cover is attached to the frame with a flexible aluminum rail arrangement.

If you crawl under the trailer and have a look, you can see the aluminum "rails" attached by screws through the rails, through the plastic, and into the frame.  

https://tab-rv.vanillacommunity.com/discussion/5282/underbelly-protector

Binghi

The problem I have found is those attachment screws rust over time and when you try to remove them, their heads break off. Then you have to drill the body of the screw out and put in a new screw. NuCamp would have done well to employ heavier duty screws.