12Volt issue - Converter? 2025 Adventurer 36Z

[theoldsp]

Hello all - tried a couple searches, not finding what I'm looking for. Hope someone out here can point me in the right direction. Our 25-36Z has not been on a trip yet - only the drive home from Atlanta to Montana. This morning, I went out to the coach and turned on the house battery switch at the entry steps. I heard the usual thud but noticed the green light was not on in the rocker switch and I had NO 12v in the coach - no lights, no panel, etc. I thought I should locate the "converter" and make sure a fuse was not blown. In all of our previous RVs, we had a converter. I can't find the converter to save my life. Inverter, no problem. Checked under the bed and underneath in forward door under drivers seat and every other bay for that matter. Nothing. I did pull off the fuse panel in the bay under the drivers seat and checked all the connections and the coach and chassis relays there. I found nothing loose but when I put it all back together, the switch magically worked and our lights and control panel sprung to life. My questions: 1. where is the converter? 2. Should I assume the coach relay is flaky and just replace it? 3. Anything else I should be looking for/at or be concerned with? The coach batteries are charged and read 13.5 The coach lives inside a shop and is on shore power for a couple days every couple weeks just to make sure everything stays charged up. The 50amp shore power seems clean and steady - meaning I have a Power Watchdog connected and the voltage for both lines is 124V, 60Hz and is steady. This ALL started because I was trying to trace down a strange flicker in the LED lights. The flicker does NOT happen when operating off batteries but does seem to occur most times I'm connected to shore power.

 

[Morich]

OH my!
I'm afraid you have just stepped into a future which I do not look forward to dealing with as time goes on!
We are quickly moving from the systems we have grown to know a bit about and into what I see as very close to not being user servicable!
I can point you to a few hints of things but when I begin to look at details of where and how to sort trouble, it quickly goes off the rails and into modules and datalinks which are beyond what most of us have the tools/equipment and certainly the knowledge we need.
Got the manual on hand for the RV? If not on hand, this link should get you to the book:

https://www.winnebago.com/Files/Files/Winnebago/Resources/OperatorManuals/Operator%202024/22Adventurer.pdf

Dropping to page 7-3 is part of where my confusion starts as we get different names/terms for the parts we used to know about!
First thing is "inverter/charger"? Then there is "load center/converter" ? All names I'm used to but different when I look for details like connections and places to check them??
I can do some snips of locations but since we no longer get actual schematics for the 12VDC, it is hard to make a good plan for checking things as much of it now goes to "modules" with data links involved! Both those are deep black holes if we don't have firm ideas of how the solid state items are designed to work.
I did snag some drawings of what the parts drawings show!

Parts Catalog

Inverter charger location?
Maybe a point to know for future is that there does appear to be a fuse or breaker on the inverter end with the fans and that might be hard to find if not aware it being there?

Then the load center is further back and has both AC and DC breakers/fuses?

For 12VDC drawings, this is what we get now!

https://www.winnebago.com/Files/Files/Winnebago/Resources/Diagram/2022/000243367.pdf

Dropping down to sheet 8 is when I begin to feel out of the DIY game on this type!

 

[Morich]

With time to look at this a bit deeper. I might have a few suggestions to chase if inclined?
One good thing about the questin is that what seems like a very large problem due to most inside 12VDC being out is actually often a sign of something smaller or easier to find. One small defect can hide easier than on that seems huge!
So if I understand correctly, much of the inside 12VDC is out? You are correct in wanting to know the converter is working but then I see a conflict in the info when they call it an inverter charger???
So I might suggest a different point to start. Things don't work, so "maybe" the converter is not working or the batteries are dead! But that may also really not be the problem but getting that power from one point to the other may be a problem?
Are you set up with a meter to test a few points if we can point out where to look?
I might want to start at or near the batteries and check the voltage first without the RV plugged into power. Are they charged or what condition?
Then to verify that the charging is working, if we plug the RV in and recheck the voltage, that can tell us lots of things. If we see the voltage suddenly jump when we plug in, we can say the charging is working and actually getting to the batteries!
That might leave it a matter of chasing why that good battery voltage is not getting to the rest of the RV??
Normally we would thing the 12VDC fuses would be a first step between converter and items using that power. That answer would be at what they are calling the "load center" in this RV.
Got a panel that looks like this or do we need to look closer for it?

 

[Morich]

But reading further, this seems an easy one to miss if we are not used to "inverter charger"?

Still looking for an easy way out!!

 

[theoldsp]

Hello MORICH - thank you SO much for not only taking the time to answer, but in such detail. So, while I know much more today than I did yesterday, I still am not 100% sure what was wrong but I'm leaning towards user error. First - your reference to the manuals. I got them all and have reviewed them - several times in fact. That said, I STILL MISSED the fact that the inverter and converter now seem to be in one component. I read that half-a-dozen times but it did not register in my mind until you restated it. THANKS... I have used the links to the drawings a couple times before and that's how I found the chassis and coach relays.

Here is where things get murky for me and I know only enough to be dangerous. Believing in my head that the converter was a separate component, I had the "Inverter/Charger" disconnect switch in the off position - probably for the last month. I mistakenly believed the coach batteries were still charging. I now know that was not the case and I'm assuming I allowed the batteries to get to a level the latching relay could not perform its job. Once I turned the inverter/charger on, the Power Watchdog showed that I was using 350+ watts and it remained that way for a couple hours - I assume that was the system charging the batteries. After a few hours, the watts dropped to about 20 and the panel inside showed 100% charged. Strangely, it showed the chassis battery was also 100% even though I read the system does not charge the chassis battery.

Here is where I'm really confused. I used a multimeter and checked the house batteries. Each one was 13.3 to 13.5. I simply checked + and - terminals on each battery. That seems high to me to not be in a charging state, so I wonder if I was not using the meter inappropriately or was checking the batteries in the incorrect manner??

Everything seems good now so again, I'm believing I let the batteries drain too far. I'll keep reading and learning. I need to learn how to really check the house batteries in a "meaningful" way.

Thanks, Jeff

 

[Morich]

Gosh! That makes me feel better!
I wake up everyday wondering what happened! I knew everything when I was thirty and now I seem to know nothing! Welcome to the club, right?
But some ideas on the batteries!
Lead acid or lithium? Lithium charge to a higher point and might make that voltage you see correct for the normal "fully charged"??
But if we are speaking of lead acid, older style, we call them 12Volt butcharge them to more like 13+, leaving them to be higher than expected for hours after we stop charging. The lead acid will only maintian and hold near 12.7 if given time after cahrging to go back to fully settled and stable. Called "surface charge" as it is a somewaht false reading we get when we can only look at the posts. School describes it as thinking of a pile of electrons we stack into the post and it takes a while to spread out through all the cells, taking maybe 8-10 hours.
Hard for us to figure on the new stuff when we get so little info!
Big one to keep in mind is that there are sneaky points we don't get told about.
There are constant steady, low level drains on both the chassis and the coach batteries, even when we turn a battery disconnect switch off---at least on the RV we have always had for years and know something about!
Safety items like CO and propane detectors on the coach side? Check for a small green LED on them and see if it is still on when you turn the disconnect off as a sanity check. I think they want them on to avoid us coming back to an RV full of gas and blow ourself up!
On the chassis side there are things like radio presets and door locks that gradually drain the battery while stored, if we don't set up a way to get the charge from the converter on the coach to tie together with the chassis!

Logic says that may have snagged you?
If you can get to both the chassis and coach batteries to do a voltage check, I like that better than trusting the monitors but that is just my cycnical side of not trusting what I can't see! When I have battery racks that are close togehter, I just use a small strap with alligator clips to tie the positive post of one to the other. As we drive, they are tied together, so the voltages are close to the same when we get home, so if we put even a small strap it is plenty big to carry the small current between the two to keep them obth charged if we are plugging in the RV and leaving the charging on.
But that knob for the inverter /charger is not one I'm up on, so testing is safer than taking my theory. Theory is good but check me before trusting???

 

[theoldsp]

Morich - you're spot on about how things have changed. Our last RV was a 2015 Landmark 5th wheel and I felt comfortable troubleshooting issues. It had in-line fuses from the batteries that you could glance in the battery bay and check their condition. It had a converter and an inverter and you put put hands on both by simply opening a door in the basement storage area. It had mechanical switches and I felt confident I could track down problems on the road. Fast forward to this 2025 Adventurer and I'm still hyperventilating after seeing the wiring under the master bed. YIKES I'm aware of the parasitic draws you refer to and I've found a couple in ours. I noticed our theater seats are hot no matter the setting of the coach battery switch. I'll keep an eye on things but for now, I'm going to assume I let the batteries drain too low.

 

[theoldsp]

NOPE! Dead Again. Was just out in the coach putting things away and the 12V lights all went out. Same as a couple days ago - this time however, I'm 100% sure the batteries are 100% charged. I'm plugged into shore power. No 12v fuses are tripped and all 120v circuits are good. Fuses in panel under drivers seat all good! Now I'm getting perplexed!

 

[theoldsp]

SOLVED: Main 12V wire going to back of 12V fuse panel was almost completely broken at the crimp on connector. New connector, screw and bolt and all is well, again.