Era70B Charge Controller weirdness!

[PbassBetsy]

So I tried to start up my Era70 after it sat for two weeks, in the coldest day we've had here (30F). Sprinter, dually, 4x4. Anyway, it didn't turn over, so I pushed the Battery Boost and turned the key. Lost of clicking and flashing lights but no ignition. I waited a bit, tried it again - no go! It had worked last year!

So I charged the chassis battery overnight, and started her up the next day. Let her run for 20 minutes, to at least get a decent charge going. (BTW, the van has all new batteries, less than a year old. The two house batteries are 100ah agm by Odyssey and the chassis is an agm by AutoZone.) But the charge controller (Zamp 30amp) for the solar system (3 - 100watt panels) is acting funny. On shore power it reads normally, but unplug and on house batteries, it very quickly will not power anything. When I start the engine, of course all is normal, unless I turn off the house battery connect switch. Then the Zamp says "b01" which means batteries are disconnected (it has never done this before when I have had to shut of house batteries for other maintenance). Also, if not engine running, nor on shore power, the house battery shut off switch (actually an actuator for a relay) doesn't work at all.

So, me thinks there is a short of some sort, caused by all the attempt to start the van, between the batteries and the charge controller - quite possibly: ta dah! - the Battery Mode Solenoid (??). I've read a lot on these forums about this problem. Since the Solenoid likely has a diode to bypass current created by the coil, I'm thinking I see evidence that the diode has failed. But I am still confounded.

I don't know how to reset the Zamp so I am not sure if it reading (low voltage) with any sense of accuracy. If it is accurate, why is there a low voltage reading when I have measured the voltage at the batteries (for some time!) and it does not fluctuate under any situation I've thrown at 'em. As far as my voltmeter is concerned, they are fully charged and healthy. So the Zamp is reading some sort of "cross-current" or reverse voltage? Then says the batteries aren't there. This must mean a short between the batteries and the Zamp, right? Could it be the solenoid? Or maybe the house battery switch/relay (which is in the same compartment under the passenger seat as the Battery Mode Solenoid.

Any help is MOST appreciated. Some perspective before I replace these expensive parts. Thanks in advance! ~ P

[Morich]

I might offer a different idea as the solenoid is so simple? What I suspect is the coach batteries will take far, far more than 20 minutes to get a good charge possibly 6-8 hours!
Then there is also the potential for them to be damaged so severely they will no longer take and hold a charge! Not to panic on that idea until proven but it can happen.

So see if this fits.

Point one is when you are not running or plugged into power, it sounds like the clicking is likely at the starter solenoid, not the mode solenoid? When trying to start, there is often enough power to move the starter solenoid (click?) but that connects power to the starter motor and there is not enough there to turn it. This can make a series of clicks if the amount of power is right as it can't turn the starter and not enough power left over to hold the solenoid so it drops off (click) but you are still holding the key so it tries again(click) and if may do this half a dozen times and all you get is a bunch of clicks with no starter turning!

When running the engine all batteries are connected together as well as power comes from the alternator. Most things appear to operate normally because the big engine alternator has enough power to do most things we want, but only as long as it is running?

Running the engine for a short time gets "some" charge in the coach batteries but it is not a through charge all down through all the cells and all the chemicals. What we often call "surface charge" as it is just at the posts of the battery. If we could see electrons, etc, we might see a little pile of them stacked up at the post and the rest of the battery empty?

Shut down the engine and the coach battery is left to carry the full load. It may/may not have enough power to move the relay controlled by the switch. You are correct and one up on many knowing that there is a second item involved in the connect/ disconnect operation! Good to have picked up that point as it can get really messy if we don't think about the relay being a latching relay.

The latching is a magnetic gizmo which will hold the last position even when we release the momentary switch! It has to have power to move it from the latched open or closed to the other .
What can catch us is if we turn on the switch but without power it stays off, we find there are dead coach batteries, so we charge them but STILL the RV is dead----because we did not actually move the relay to close when we had no power. We only pressed the momentary switch the right way but nothing real happened! Not knowing the switch is momentary, they feel they turned it on but still with good batteries things don't work. Good batteries first, THEN turn the disconnect on to get the relay to move!

I suggest first getting a full charge in both the chassis and coach batteries and that will take 6-8 hours and then look again at what seems to work/ not work!
To be sure the batteries are still good and will hold a charge, try charging them, let they get stable for at least 6 hours and then look at the voltage again to look for a more accurate idea of their condition.

The whole setup is based on good battery power and that can get difficult to figure when we are charging but not getting a full long term charge or batteries which may not hold that charge for more than a few minutes.

Note to check? We don't know which year you have and some will have the solenoid while the later model may have a solid state version called a battery isolation monitor (BIM) doing the same but solid state instead of the electro-mech solenoid.

Important note? The battery disconnects DO NOT remove all the small drains from either the chassis or coach battery when we store for long periods! Safety items like propane and CO detectors on the coach and radios presets, door locks. and any automatic functions like steps are often left on the chassis

[PbassBetsy]

Thank you for the thoughtful and quick reply, Morich. My Winnie is a 2019 Era 70B with one extra solar panel (3 total). Following up on my charge controller and house batteries problem: I did as you suggested, make sure all batteries are fully charged and healthy. I did that with my trusted 30 amp charger. Chassis and house are 100 percent. Then I again checked to see if when switching the house battery relay actuator switch I was to get the weird metering from the charge controller. Yup, if fact on the house batteries, the voltage drop was substantial and I got led overhead light flickering. This made me very suspicious of the controller but also of the battery relay, as I saw on its label that it has two diodes across the relay. Me thinks one of the diodes was going south, but not quite open yet. So I took off the passenger seat and got to the control box. To test my suspicion about the relay, I metered the large lugs, one from the battery boost solenoid (and the house batteries - right?) and the other with green tape, which I think is the generator input. Anyway, good 14.7 volts on all lugs. Then I pulled the signal plug on top of the relay (at least four contacts, two no, two nc). Naturally no house light etc. When I plugged it back in, I got a consistent (now) b01 at the controller, and the battery relay actuator switch no longer works. So at least it is consistent now (diode finally shot?): When the shore power is applied, the converter powers everything (normally) including the house battery on/off switch little green led light. But now (after my unplugging and plugging in), the house battery switch does not work at all (relay does not actuate) in either shore power or house power - which there is none, even at the yellow tagged wire to the solenoid.
Confounding to say the least! If I replace the relay (thinking that the internal diodes are shot) and I still don't get house battery power, it seems there is another circuit breaker or fuse that was failing before and is now open - keeping power from the batteries to supply the house. Where exactly the controller is in all this is mysterious too. Where does it get its power to light the leds and lcd? I thought the Zamp only controlled output of the solar panels to the battery. It clearly measures battery voltage no matter what source is giving them juice, but also seems to measure the current being drawn from the source (either battery or converter). Might I have a bad controller?

I have checked the two fuses on the converter (2 at 30am) and they're good - of course, because the microwave, etc would not work. I am able to simply unplug it to test whether house power is getting to anything.

So the evidence at this points points to: There is something stopping power from the house batteries getting to the control box under the passenger's seat. It might be, oh no!, the fuse at the batteries (150amp)? I'd have to lower the batteries from underneath the rig, disconnect them and check it with a meter. Or might there be some other circuit breaker somewhere along the line (seems unlikely since the cable is so large)? There is an inline fuse on the chassis battery positive line to the solenoid, so there could be that big a fuse somewhere along the house battery line.

Any help is appreciated. And thanks for your continuous support of we noobs.
~Pbass

[PbassBetsy]

Here's a photo of the control box. None of the circuit breakers were tripped (you can't push any in, none popped out).
You'll notice a relay that is tucked under the in-line fuse to the chassis battery. About four yellow wires going to it. ??
And the silver-colored box is a controller box for what? The chassis? It has a lot of little multi-colored wires to and from it. I doubt it is for the house 12v system. ??

[Morich]

More info to clear or BOGGLE the Mind!

This drawing shows what you find under the seat in the picture. The battery cable colors match but they do not show the other box you mention.
https://www.winnebago.com/Files/File.../000027700.pdf
Click these snips to see better!
The drawing to ID the parts.


The red and yellow marked are battery cables from chassis and coach batteries that are connected when the solenoid operates! That solenoid is controlled by the blue marked LR as battery and FM as ground to power the solenoid coil.
Then there is short cable to disconnect relay left side. When relay closed it passes power through to right side. On right side there are wires which go to generator starter solenoid and to many of the coach breakers. Wire KKF that I marked orange does that .
A good thing to know is the purple lines as they take power to chassis breakers and to coach breakers BEFORE the disconnect. That part is left hot even when we use the disconnect switch! They WILL run the batteries down when stored!
When looking at small wires from Winn. they ID them with stamped on the ends!

When you find the ID, you can then go here to get info on from and to of that wire!
https://www.winnebago.com/Files/File...ical_guide.pdf

Lots of hunt and peck required to find what they do!

I found this in the parts catalog here:
https://catalog3d.winnebagoind.com/menu/Parts.htm


It shows a big speaker but nothing about the box you ask about? Audio wires are often ignored, so I might guess it has something to do with audio and the speaker?? Audio may/may not have ID on them. Never chased audio wires much, so not sure of that!

Review of what I know?
The solenoid is just a switch that uses chassis battery to open/close the contacts that connect chassis and coach battery together. I don't know of any diode, etc in it but if it thumps when dash switch is pushed, or engine started, that says it moved closed. We can tell is the contacts inside are good by watching the voltage on the right (coach) side as we rev the engine. As the engine runs faster the voltage on coach will goes up and down showing the coach side is getting power from the chassis side!

The disconnect really just opens/closes contacts, so if we get 12V on the right side of it and the wires are connected good and clean, the coach breakers and generator starter should be getting power.

So if you start the engine to get power from the engine alternator going to the coach as well as chassis, then try to crank the generator, if it starts all the RV should then be powered as the generator takes lots more power than anything else! If it is getting enough, the lights should be no problem!

Idea is that if we can get enough power through the relay to crank the generator, the other smaller stuff should be fine! But if lights are flickering or dim. maybe something like a breaker along the way to them is not good?

[Morich]

Got some more time to look at this and now have a couple ideas.
One thing to check is that the converter is getting 110AC power and that it then sends the
12VDC to the coach batteries.

This should happen any time the RV is plugged into 110 or if the generator is running.
A snip of how that gets point to point:

Power comes in as red or green line from genset or cord, the transfer switch chooses which and passes the AC on to the load center as blue line shows.
At the load center, there should be a 30 amp main breaker which passes it on to the other smaller breakers for each circuit like outlets, microwave and one for the converter.
If plugged or running generator, the outlets and micro, etc should all be working. A quick test that power is getting to the converter may be if you are in a quiet place, you can often hear the converter hum a bit??
If you click the converter breaker on/off you may be able to hear the converter change sound? That would mean it is getting 110AC power to it.
And we will assume it is making 12VDC!
So if you have a meter on some part of the coach batterie power, (like at the right side of the mode solenoid?) or any place in that path, You should see an immediate change in the voltage when you flip the converter breaker on and off!
When checking this, don't have the engine running nor pressing the dash switch to avoid the two batteries connected together and confusing the answer!

Plugged in or generator running, but with the converter breaker off. there should be some level of power at the right side of the solenoid, then when you flip the breaker on, that reading show jump up to show the charge from the converter is getting to the batteries!

But if power is not getting from converter and on to the solenoid, it might get ugly to find as the batteries are hung up underneath and in back of the RV. Hard to get to them!


The one on passenger side shows the 150 amp fuse you mentioned! And lots of cables that can be dirty or corroded. Just as a thought, we get lots more corroded cables than we do failed parts!
Hope not but it's still true??

I'll let you look it over and see if any of that makes sense?

[PbassBetsy]

To make a long story short: after checking every inch of the control boxes and fuses, I came to the conclusion that the break in house battery power to the coach had to be at the battery. So, though I was loath to take these 75-80lb batteries down, I did it with the help of two scissor jacks. After removing all wires and their tie ups, I removed the single fuse and holder from the passenger side battery box. SURE as RAIN, that fuse was open, burned up (150 amp for the inverter circuit). And the other tell-tale sign was the line to the coach (terminating at the battery cut of relay and boost solenoid under the passenger seat) was connected on the load side of the fuse. Only the inverter is supposed to be connected to the fuse. So, when I tried to use the Battery Boost switch to start the engine, the fuse partially blew. Then when I tried other loads to the house batteries (individually, the water pump, the ceiling fan, the fridge, the overhead LED lights) all failed with strange readings from the meter on the solar controller (Zamp - which meters house load). After I disconnected the control wires plug (yellow and white) on top of the battery relay, then reconnected the plug, the surge of draw to activate the relay was enough to fully blow the fuse. Then I had NO battery power to the house (converter power and engine/alternator power were fine). Thus I was looking for the fuse at the battery.


Only the inverter line in the 2019 Era 70B is fused at the battery. !! I replaced the fuse, then routed the other positive/red leads to the correct lug (cross-over + and house supply + and inverter fuse supply side). These three red wires all are supposed to be connected to the battery lug directly.


I noticed that in 2020 + Eras they put three batteries in one box and fused the supply line with a 400 amp fuse, as well as having the 150 amp fuse for the inverter. Smart! Too bad 2019 isn't so smart - not to mention numerous other manufacturing defects!
So, she works like she is supposed to now - yea!
Thanks for ALL your help!
~Pbass

[Morich]

Sounds like a good result. The trip had a lot of bumps but it's getting there that counts!