House Battery Charging Issue 2019 Winnebago Vista 32YE

[Russ-USA]

2019 Winnebago 32YE

We are having an odd problem. The house battery charges fine from generator and shore power. When charging from the alternator the chassis battery charges but the house battery seems to be on a delay. The house battery slowly discharges even with the engine alternator running for about 20 plus minutes. The voltage gets down to about 12.5v from about 13.3v then it begins to charge.

The circuit is the older solenoid-relay setup and not a BIM. I don't recall there ever being a delay before. Below is the diagram we have in the unit. The relay is made by Tyco.

I guess the question is does the system first charge the engine battery then charge the house battery? Does not seem it is that sophisticated.

Thank you,
Russ

 

[Morich]

Correct on this not being a complex system! When the alternator is charging the chassis as any normal car/truck does, this solenoid only works to connect the coach to the chassis battery wiring. That solenoid is about as simple as it can get!
What sounds very likely is that you have a solenoid which is worn/arced/corroded and only closes to make good contact once in a while. Just often enough to confuse you!
It IS possible there is a dirty cable connection between the solenoid and the coach batteries and it comes and goes, but it it really common for the solenoid contacts to get burned.
But if it seems the same voltage is on both big lugs with the engine running, there is a different spot which may be getting corroded, dirty, loose to make the voltage at the coach battery post jump up and down at random times.
Take a look at this "mega fuse" and holder near the batteries?
Battery stuff always seems to need attention and cleaning!

To help sort the cables if the tape has not fallen off, this may help with the color code markers:

Good luck on the chase!

 

[Russ-USA]

Thank you Morich! I did check connections and they seemed tight and reasonablely clean. I am leaning to the solenoid and since I will be in that breaker box taking things apart the relay will get replaced at the same time.

Thank you for the great support. Will let you know if that fixes the issue.

 

[Morich]

Maybe keep in mind that a strap between the two big lugs will act to keep the two groups connected. That might let you do a down and dirty cheap test of all the other parts and connections. Idea is that you should have the coach with converter, when plugged, getting to one side and the alternator, when engine runs, on the other side!
At that point it is much like two buckets of water connected! Power will run from the higher side to the lower until they are even. If it doesn't, then there is something wrong with the path at some point.

 

[Russ-USA]

Followup - replaced solenoid and relay. No change. Actually it seems worse since the charging never kicked in after 30 minutes. Not even intermittently as before.
Going back in a bit after lunch to recheck voltages and connections. Must have missed something.

 

[Morich]

Okay that seems even more likely to push it over into connections that are flaky and changing.
This drawing shows the locations of the cables and connections on the chassis and some of the coach cables.

https://www.winnebago.com/Files/Files/Winnebago/Resources/Diagram/2018/000131231.pdf

But the main points I ight suspect are on the frame jus in front of the entry door/passenger side. An then an easy one top overlook is that we have to have a good ground! That ground buss bar looks to be down behind, maybe below the batteries. On the frame where we don't see it and easy to forget?

This ? big fuse holder down on the frame where there is lots of water and and slop?

Or maybe the grounds for both are down somewhere behind the batteries?

It's like Easter and we never know where they hid the good stuff!

 

[Russ-USA]

Follow-up 2 - FIXED! Thank you Morich. Funny story, and I feel very dumb. When I replaced the solenoid and relay I had placed the old solenoid next to the new one in my parts bag. Somehow I had grabbed the old one again and reinstalled it. When I went back and opened the breaker panel I knew what I did right away. Swapped the new one in, put everything back and fired the RV up.

The house battery is charging off the alternator again! Thanks for the help!

 

[Morich]

My old excuse for things like that?
The only ones making mistakes are those who are working!

So we have a choice? We risk making mistakes or we admit that we never tried to do anything!
Now go have fun!

 

[Bryon Carpender]

Good job getting that fixed according to my reading those relay solenoids are only good for 3-5 years need replacing
Makes sense when you calculate how many times they switch

 

[Morich]

Three to five years may fit if you drive it often but if it sets as much as many RV, it may last 15 years!
Another factor in how long they will last will be how we use the coach and RV. If we tend to use the RV to camp without hookups, the arc will be much different than if we rarely run the coach batteries down very far.
The arcing between the two points depends on the voltage difference. So if we connect a chassis battery which may be running above 13 as we start the engine to a coach battery that is drawn down to less than 12, we get a different arc!
One of those things that I find work for so long in the use we make of the RV, that it is not one to worry about the issue.
I've changed starter solenoids several times on boats and cars but never a mode solenoid on my own RV!

 

[kamphiker2]

Good job getting that fixed according to my reading those relay solenoids are only good for 3-5 years need replacing
Makes sense when you calculate how many times they switch

My experience also 3 - 4 years before these entry level contact solenoids fail as they are not a true 100% Duty Cycle. Trombetta is one of the suppliers to Winnebago. I have always replaced my failing ones with a true 100% Duty Cycle Contactor also from Trombetta but the "Bear DC Contactor"
Part# 114-1211-020

Cost around 60.00 delivered but worth the higher cost.
Slightly larger than the OEM one Winnie installs.

 

[kamphiker2]

My experience also 3 - 4 years before these entry level contact solenoids fail as they are not a true 100% Duty Cycle. Trombetta is one of the suppliers to Winnebago. I have always replaced my failing ones with a true 100% Duty Cycle Contactor also from Trombetta but the "Bear DC Contactor"
Part# 114-1211-020

Cost around 60.00 delivered but worth the higher cost.
Slightly larger than the OEM one Winnie installs.View attachment 1953579

Attached Picture of Old Contator in my hand and the new Bear family contactor installed in the background. This is installed on my 2020 Vista 27P

 

[Russ-USA]

Interestingly enough, one month prior to the mode solenoid failure the starting solenoid in the Onan 4000 generator also failed. Replaced that one and the gen set starts fine now. The one in the gen set was not labeled but it looks almost identical to the mode solenoid I replaced.

Years ago I worked for a product safety certifier (UL) and I had a solenoid mfr and a few relay/solenoid manufactures that I visited. The solenoid mfrs products looked the same as the ones I replaced in the RV. They tended to use the same housings and just changed the internal washer thickness and side contacts depending on the amp rating needed.

 

[Morich]

And this brings up some techie type questions that you may have more knowledge about? Does the thickness of the washer actually do much good for making the solenoid last longer if the issue is not the overall warming of the washer but the pitting?

 

[Russ-USA]

I don't believe it will last any longer. The extra thickness will handle higher currents but the higher current one will most likely be used at the higher rating. On the other hand, if you use say a 200 amp rated solenoid on a 10 amp max circuit I would think it should last way longer. Just a guess.

Switches, relays and solenoids do go through extended cycle testing if third party certified. Some cycle testing can go as high as 100,000 cycles or more. Testing can be in the form of resistive and inductive loads. The mode style solenoids I used to look at used to be in a category called industrial truck solenoids. I don't remember if they did any cycle testing on those. I would think they did.

But that is one reason why you pay a higher price point for third party tested products and the Chinese knock offs are usually cheaper. Testing things adds costs of course. Paying a third party to test your products adds even more.