House Batteries Good, changed out Aux on/off Switch still no power

[bwfkwf]

Just used the RV last month. All worked fine. Went out to load a few things in it for an upcoming trip and no power from house batteries. Check batteries. They are good. Event took to NAPA and had them do a charge and check. Replaced and nothing. Thought maybe Aux Switch. Changed that out and nothing. I'm at a loss. I have a 2007 Itasca Sonova. Any thoughts on what it might be?

[Ontario Don]

Hi - How about downstream of the batteries... enroute to the charger / converter distribution and beyond? Have you got a CB or fuse on that box?

[Goodspike]

Did you have the batteries disconnected during that month? Either at the shut off switch or actually disconnected? If not, the batteries were probably dead within a week from phantom draws, like the smoke and propane detectors, etc.

[bwfkwf]

Didn't disconnect the batteries. We have been going back and forth to the RV do little work on and everything fine. I initially thought battery draw/dead. Hence why I took them out, cycled them and took to NAPA for a check to ensure they are good. From that I assumed maybe the switch. Still not working. I have been researching and thinking it may be the converter gone bad. From what I have been reading...a bad converter will interrupt the power not allowing anything to come on from the main house batteries.

[Morich]

That's an area with lots of potential for faults, so the first step is to find what is actually inline to do the charging and that is different on different RV, so since there are six different models of Sunova from 26 foot to 35 for that year, what model do you have?
The wiring diagrams are here but they do take a bit of getting used to reading them and I really like to start with knowing I'm looking at the right one.
http://www.winnebagoind.com/diagram/Wiring.htm
Lots things we can rule out with testing and it's lots cheaper than changing parts!
For a first check if you go back out to the RV, try starting the engine which should then connect the start battery which is charged by the engine alternator over to the coach batteries. That all lets us do some charging on the coach batteries as we drive---if things are working right. Knowing that works or not can give us info on what to look at further. So try an interior light or something that works off 12vdc while the engine is running? The alternator power going to the start battery and then also connected to the coach batteries and finally getting to the lights, will rule out lots of things like blown output fuses from the batteries, so a big start on which way to look.

[bwfkwf]

Thanks Morich....the model I h ave is the Itasca Sunova 35J (35ft with Bunks). Sure don't make these issues easy do they.

[Bones2003]

Not sure what you mean by the "Aux Switch". I know some coaches have an Aux Switch which is a momentary switch to connect the house batteries to the engine so that you can start the motorhome with a dead chassis battery. I also have seen a "Main/Aux Switch" that allows you to power the radio from either the main chassis battery or the coach batteries. I guess that leaves the "Battery Disconnect Switch" also known as the "Salesman's Switch" which disconnects the house batteries from almost everything through a battery disconnect solenoid. When you toggle the switch do you hear any type of clicking noise and, in the past, did it used to make a clicking noise when it worked?

[bwfkwf]

Yes, that is the salesman switch I was talking about. I have to say I don't hear a clicking noise when I hit the switch off or on. In the past I use to hear a clicking noise when hitting the switch.

[Bones2003]

Battery disconnect solenoids are somewhat common failure items or perhaps just a problem with the wiring connections to the solenoid. I think there are some pretty good threads online about how to troubleshoot that solenoid - including whacking it with a chunk of wood or rubber mallet to free up any stuck contacts!

[bwfkwf]

I'm not sure where the solenoid is located on my rig. Researching that now. Man this is driving me crazy.

[DavidM]

Do you hear a click when you turn on the salesman switch? If so that will help you find the solenoid. If not then possibly the switch is bad or has a bad connection. But more likely the solenoid that that switch controls is bad. Sometimes the solenoid will click but will not provide power- bad contacts or sometimes the solenoid won't click and its coil is bad or there is a bad connection.

David

[Bones2003]

Originally Posted by bwfkwf

I'm not sure where the solenoid is located on my rig. Researching that now. Man this is driving me crazy.

Hopefully Morich with chime in because he is really good at digging through the Winnebago drawings to find things. Otherwise, look in your basement compartments (probably close to the batteries) for a black metal box with two silver colored thumb or knurled screws holding on the cover. It should also be labeled.

[bwfkwf]

When I hit the salesman switch I use to hear a clicking noise (the the sound of the switch itself). But I'm not hearing that now. Now to isolate where that solenoid is located.

[Morich]

Originally Posted by bwfkwf

Thanks Morich....the model I h ave is the Itasca Sunova 35J (35ft with Bunks). Sure don't make these issues easy do they.

Okay, the bigger the bus the more relays, so we can start with that. You do have two that tend to get confused as they do kind of the same thing. One is the battery disconnect relay and has several small wires and smaller and then the battery mode solenoid which tends to be more a silver item with big lugs on each side. Do you know where there are couple things like that and both of them do click at different times, so we can start there if you can locate them.
My simple idea is that the Aux switch usually is a momentary switch which kind of works like giving the start battery a "jump start" from the coach batteries as long as we hold the switch.
The battery mode solenoid ties the two strings together once we have the engine alternator putting out power and lets us charge both.
But that is only good for the models I've looked at and may not be true on all models, so needs checking.
Assuming the RV is not home and handy to get to it?
Do you have any experience with electronics and maybe have a meter or do we need to tailor the testing more to what you know and have? Just need to know what level to fly!

[Morich]

Not looked but possible under the passenger seat? That would put it closer to hear the click.

[Bones2003]

A quick search shows that your battery disconnect relay is located in the chassis electrical box which is located in the top half of the basement compartment that is between the main motorhome entry door and the front passenger tire. It is in the back of that compartment so it looks like a nightmare to get good access to it. I hope you have long arms!

[Morich]

Found the panel to look for but it may not be easy to get to it if it is like what I have as it is hidden behind a fuse panel.
Picture of the outer panel.
Also pictures of what we might expect to find inside and behind that fuse panel. The battery cables should have tape on them to label which goes to what item.
I marked them as the color tapes should be on the cables, so that may help find which items are which?
So the question may be what it takes to get to them and whether we "require" that much work or do we need to try doing it by listening for clicking and testing some easier way? Will stand by and let you mull that one over!!!
I'm NOT busy but some folks may be wanting to go somewhere RIGHT NOW!
Try clicking the pics to get a better view?

[Morich]

Whoops, looks like a conflict of info ? Or is what I'm seeing in behind like you see?
I'm looking at this drawing:
http://www.winnebagoind.com/diagram/...ire_154491.pdf

[Morich]

Mayber some info on why we feel it important to look at this relay?
The relay is shown on the right on drawings but may be anyplace, right or left, so sort for the correct one by the wires.
Then what we expect to happen, is when the battery disconnect switch is pushed momentarily, the control wires I've marked in brown energize the coil in the relay and make it move either open or close. The coach battery is coming in on the yellow marked wire to a big lug on one side and when the relay closes and that coach battery "switch" inside the relay makes the coach battery power come out the other big lug.
This is a tricky operation though as we do not want the power used to close this relay to stay there and use battery, so they "latch " it using a magnet so that it stays after we let loose of the momentary switch on the dash!! That magnet should hold it in the last position we have chosen until we hit the switch again but to make it move the other direction, we have to reverse the polarity of the control wires. So one can get a real question if we are looking at the wires I've marked brown and find one battery and the other ground ----because the next time we push the button, they reverse and that makes the coil in the relay move things the other way.
So if you look at those two wires with a meter and find battery and ground one time while the switch is pulled and then nothing when the button is not pushed and the next times you find ground and battery reversed, that is what we want!!
The end result is that we DO want the big lugs on each side to be connected and stay until we push the switch again when we DON'T want them connected. Connect and disconnect, right?
So if it is really hard to get to these, there may be a way around it, for short term.
These can stick, so if you can just see it and give it a good bump to "unstick" it, you may be able to get lights and the 12volt stuff inside to work again.
But one big thing to keep in mind is that sticking usually/ almost always comes back, so look at changing it.
Sorry but I suspect that will give you at least a week's worth of heartburn to think over, so see what it looks like and let us know?
Happy hunting!

[Morich]

And for those who like videos and find the written description difficult, here is a video that makes it much better to see:

https://www.youtube.com/watch?v=UGxJs5XaSWY