AUX battery button not working

[Sk8Surfr]

My starting battery is shot...

It's easy enough to obviously replace - but I tried to hold the AUX switch - and it didn't work. I can hear the solenoid... but I can't start the RV

Here is a pic - this is the solenoid, correct? At first glance I thought maybe because there is a fuse missing? (is there supposed to be a fuse in the top right)?

I put a 5amp fuse in... still nothing.

[Morich]

No, I believe that would be the battery disconnect, not the mode solenoid!

The solenoid should be very close by but more a silver metal item, not the bakelite.

This is the drawing for your RV . Note the wire colors and size marked to locate which wire is correct?

Click this drawing to get better view!


When the solenoid operates, it gets power on the small wire LR , either when you push the boost or aux switch on the dash OR when the engine is first started, If you are near or can feel the solenoid, you can often hear or feel it move.
That movement connects the big cable from the coach batteries on the left to the big red cable from the chassis battery on the right! That little triangle where it says 1 is where we would find the chassis battery.

For an emergency situation, this is like jump starting your car using a battery oin a dfifferent car? if you REALLY NEED to get the engine going, you can use heavy wire like a jumper cable to tie the left and right big lugs together!
Expect some sparks like you might get when jump starting a car, though!!

Carefull if you are nervous of a bit of sparks! But if no chassis battery of any sort, I'm not sure what that gets except to start one time to drive until you shut it off again??? Maybe works, maybe not to start?

[Morich]

On thinking what happens if there is NO 12volts on the chassis, I think there will be no movement on the mode solenoid at the places where I marked red X's!

But if one wanted to test the solenoid without having a chassis battery. you can do that.
If you put a small jumper between the big coach battery cable on left and the small wire on the center post, it will use coach batttery to make the solenoid move. If you first have NO 12 volt on the right where the chassis battery would normally be found, then put the jumper on to move the solenoid, you should then see that 12 volt battery on the right side as well, meaning that the solenoid moved and closed the contacts.
I would guess there would be nothing happen when pushing the dash switch without having any chassis battery to get the power.

[Sk8Surfr]

Found it! 13.3 volts at the house side - 10.0 volts at the chassis side - even when I click the AUX switch...

The middle purple wire on the solenoid registers 13.4 volts when I hit the switch... but I guess it's not making a connection to the other side?

Second question - on my battery disconnect - should there be another fuse?

[BobC]

Morich is the expert, but just to be clear so there's no confusion in the terminology used to describe the switches and solenoids:


Sk8Surfr mentions the "Aux" switch. According to the 1999 Adventurer operator manual, there are actually two switches on the dash with Aux in their name.

1. Aux Start Switch - Combines the house and starting batteries for an extra starting boost. It triggers what Morich calls the "mode solenoid".

2. Aux Batt Switch - Connects and disconnects the house battery bank. It operates what Morich calls the battery disconnect solenoid.

The location is shown on page 2-12 of the operator manual. The operation of these switches is located on page 2-15.

https://www.winnebago.com/Files/File...Adventurer.pdf

[Morich]

Good catch on the naming as it is a vital difference that I had not run across yet. That left me "assuming" that the AUX switch was what is named "boost" on some RV and for connecting the two battery groups.

So we need to get more details on which aux switch??
Are you speaking of an aux switch that connects batteries together or an aux switch which connects/ disconnects the coach batteries?

Not nice to have them named so closely when they do such different things!

So maybe we need to dig deeper and feed a bit more info on how Winnebago does things.
They label wires to help ID them but it takes some looking to find the info.


Once we find the wire labels, we can go to this sheet for sorting out where that wire comes from/goes to and that often leads us to figure out what it does. Like if it feeds from a fuse or ground?

This chart is the magic "decoder" list:
https://www.winnebago.com/Files/File...ical_guide.pdf

So if we look at the mode solenoid which is the shiny metal one, we might spot wire LR as being a small one and we can sort out what it does from the chart. It brings power down to operate the solenoid! That connects to the switch for aux start switch!

But then if we want to talk about the aux battery disconnect switch, we get lots different info and part of that is the ID of the three small wires.
Looking on the ID chart, we can find those three listed as well as a fourth one not shown on the drawing for your RV.

Click these snips to get a better view!


Looking at the battery disconnect relay, we can spot the wires LG,LH,LJ as small control wires if we match it to the wire ID chart.

This is a "special" type relay that moves when we send a signal to it from a momentary switch but then when we let off on the switch, we want the relay to stay either turned on or turned off and do it without using battery power full time! So they use a latching relay which is a normal relay but with the added feature of using a magnet to hold the rleay in the last postion.
The magne tuses no precious battery all the time, just when we want to move the connection from on to off or as they call it "engage or disengage".
It a great idea but it takes time to get their language sorted out!

When you get down to looking for a second fuse, it may be that you are confusing two different rV as there are some which have an indicator light on the switch to tell if it is on or off but I suspect not on
YOUR RV.
See the little tab on the top right of the disconnect realy? I suspect that would be where a fourth wire called LK would be and would power the indicator light that I'm guessing you do not have, so no second fuse either! ??

But this wiring comes from the battery disconnect (aux bat. switch?) down to the relay. Lj brings battery power from the fuse and LG or LH make the complete path to engage or disengage the latched relay!

Testing?
Once you get good chassis battery, things should work like this.

Push the momentary aux start and the metal can mode solenoid should "clunk" loud enough to hear or feel it with a hand on it. That can give the weak chassis battery a boost or jump to start!
When you let off the switch it pops back and the solenoid falls off to disconnect the batteries from each other.

Pushing the battery disconnect one way should make the relay move to either disconnect ot if pushing the switch the other way, to connect the coach items.
Inside lights on, inside lights off? Feel the switch and you can tell it rocks one way and then flops back when released or can be rocked the other way!

Lots of little details to work out and just because one RV looks "exactly" like another, there are small details which are different on each. If they were the same, they would have the same names!

[Sk8Surfr]

My Aux Battery disconnect works - Yes, when it's off - no lights - no Gen start. etc.

Its the MOM switch - I hear the solenoid click... and the center lug says 13.4 volts (same as the house batteries) but the other side of the solenoid is still reading 10 volts (same as the starting battery)

Bad solenoid?

[Sk8Surfr]

reading more... do I need to hold the the AUX (MOM) switch for an extended period of time?... like... minutes - before I attempt to crank it?

Or - does it act just like a jumper cable - and holding it SHOULD give me enough to start the engine?

[Morich]

Sounds like the contacts in the solenoid may be burned and not making good contact. The solenoid should move almost imediately as you push the switch!

To start the engine when in doubt about the battery, just push the switch at the same time you turn the key and it should be working. If you can get a helper and say "push it" you can feel it thump if you have a hand on the solenoid.

A seond way to get the idea of whether it is working is to use some wire to tie the big lug on the left where there is coach battery to the small center lug and hear/feel what to expect. That is just using the power from the coach batteries instead of the power from chasssis battery from the dash switch. All it takes to move the solenoid is 12volt power from any of the battery as it runs down through the coil and gets to ground using the metal of the solenoid screwed or bolted to the RV.
One point to keep in mind if the solenoid is not moving is that the mounting has to be a good solid ground. If you take the solenoid off the metal, the ground is gone and it won't work!
Some RV use a three post solenoid while others use a four post and the added post is to bring ground as well as using the mounting screw.
It is a BIG contact, not some small thing. The inside is pretty much a coil with a metal rod in the center and at the end of that rod is a "washer almost as big around as the round part of the solenoid. Like a half dollar or more slapping up to the lugs which are the mashed end on the bolts that hold the cables. So you can see it is a thump to hear or feel!
IF you feel it move and the voltage doesn't go to near the same on each side, the connection is not being made.

These are a pretty common failure point as they operate every time we start the engine and do carry a fair amount of current which causes arcing at the contact point.

[Morich]

Thinking about this overnight, it occured to me that one of the best ways to fix RV electrical is often just getting the batteries back to full charge.
Since you are seeing the 13 volts and that is more than the good lead acid battery will hold, there has to be some form of charging going on! Do you have it plugged in and the converter is charging the coach side?
If you are wanting to get the chassis side charged and don't have a small charger on hand, we can charge both sets pretty easy.
Both sets uses the frame as gorund, so getting that charge from one to the other can be as simple as connected the positive posts of one coach battery to the positive post of the chassis battery! That makes them all work the same as one big battery as long as that wire is on!

Not a good thing to leave on all the time as then they would also ALL run down at the same time, but for short term to get tham all charged back up,let whatever is charging one, do the whole thing.
Charging is a slow thing and will often take 6-8 hours if a battery is way low, so maybe just give it lots of time.
Another point I noticed is that there seems to be some different wiring in one of your pictures, so watch for things that may have been added and notnormal. Sometimes things get improved and sometimes not???
Dirty corroded connections is often a problem, too.

[Sk8Surfr]

Yes, it is plugged in. If I hook up the house and starter batteries don't they try to normalize? Won't the good batteries drain down a bit?

I plan on going to get a good new battery anyways - I figure I can still troubleshoot and test the solenoid via voltage and swtich with a. good battery.

[Morich]

Yes, all the batteries will try to move to the same voltage, much like water in buckets tied together.
But if the RV is plugged and and the battery cutoff switch is on so things inside are working as normal, that gives the 13 + voltage reading you are getting and if you connect chassis to the coach batteries, they will ALL be getting the 13+ for charging!
We might think of it like we have two cars only they are both on the same frame for the same ground. That's like one side of the jumper cables we put on the negative posts.
So if we add a wire between the positive posts, we have much the same as jump starting two cars, except we are getting the power to charge them from the AC cord feeding the converter providing that charge. Normally we use the alternator on the second car but it works the same using the ocnverter.

Point that you may know but we often forget is that when we start charging a battery and read the voltage it may look really good and say it is 13 or more but if we take the charge off and wait an hour for the chemicals to settle and get stable, we may find the battery is still really low.
Surface charge is the common name for this as it is a reading we get right at the "surface where the post is and down in the batterym the chemicals may not have got any change yet.
Sometimes compared to putting ink in a hole in a barrel? If we put in a teaspoon of ink and look in the hole, we see it really black but if we come back in an hour we may not see any black after it spreads all through the barrel and gets stable.

Using voltage for batteries is tricky because if we look right after we take the charger off, we may just see what the charger was doing, not the full story!
That's why I thought you must be plugged because even a really good battery will not hold a charge over about 12.8! When you have been charging recently or still charging, you can see 13 but that is kind of like looking in the hole while still pouring the ink in!

I say the voltage on both sides of the solenoid should be the same but I guess there "could" be something so badly wrong with the chassis battery that you could only see 10 but that would take a big short of some kind and I don't know of it ever happening. If you were working the converter that hard and it still could not get the battery up higher than 10, fuses or breakers would be blowing somewhere on the feed to the converter, etc.
If you want to do a bit more work testing, take the cable on the right side that goes to the chassis battery totally off the solenoid and see what the voltage on just the lug coming out of the solenoid say when you press the boost or AUX switch.
If you see 13 volts from the converter chargin the coach batteries at the left lug and the solenoid is supposed to connect that to the right side and you only see 10, the solenoid contacts are not making a good connection for sure!

Sometimes the name solenoid sounds complicated but it is just a switch that moves by electronics instead of our hand. So if you get power to one side and it doesn't get to the other side, that switch (solenoid) is not good!

[JR314]

Check out this video from AZexpert. I think it may help identify your problem. https://youtu.be/MGrfmbsJEuY

[Morich]

Originally Posted by JR314

Check out this video from AZexpert. I think it may help identify your problem. https://youtu.be/MGrfmbsJEuY

I do not want this to sound like a knock on Az Pete as he does know what he is doing!

However, I don't want folks to think what he is doing on the Monico has value for what we do on many Winnebago as the two are so different.
There is no board on the Winnebago as he is dealing with on the Monaco. No lights to read, etc. as well as totally different solenoid. Never seen a latching solenoid for the Winnebago we deal with.
There is a latching battery disconnect relay but that is pretty much a different part of the battery system!
Just part of the process is to know what each RV has and not confuse what works for one as being the solution on another.

There are times when the solenoid on Winnebago stick and it can give some of the same situations as he has on the Monico but his problem was that somebody installed the wrong solenoid and in the Winnebago, when it stays connected it is more likely burned contacts sticking as there is no latching function.

[JR314]

Sorry if I linked to the wrong video. The one I intended to link was related to a solenoid with burned/corroded contacts. After cleaning the contacts, the house and chassis battery were able to be connected again.

[Morich]

Originally Posted by JR314

Sorry if I linked to the wrong video. The one I intended to link was related to a solenoid with burned/corroded contacts. After cleaning the contacts, the house and chassis battery were able to be connected again.

Okay, no problems with me over getting the wrong links added. It's one of my favorite things!
Yes, Fully agree that cleaning the contacts can make them last a bit longer. I have never been able to get the metal can off well enough to make me want to do it very often but I do know the contacts inside are like a big metal washer and it would not be hard to buff them up again.

[cbeierl]

Originally Posted by Morich

I do not want this to sound like a knock on Az Pete as he does know what he is doing!....

Just so folks aren't confused, I don't think azpete (HWH expert) is involved here--the video is by AZexpert.

[Morich]

Originally Posted by cbeierl

Just so folks aren't confused, I don't think azpete (HWH expert) is involved here--the video is by AZexpert.

Argh! Another case of careless reading! there must be two different Arizona guys that look like experts. Acutually what impressed me was that he was able to hold the two probes in one hand while taking readings. I'm a guy who uses alligator clips to hold one!

[tim myers]

Did not see this mentioned, but if you wanted to verify that the issue is with the solenoid not engaging or bad contacts, could the OP use a jumper cable to jump across the solenoid as in connect to the house side of the solenoid and also the chassis side of the solenoid, since this is all the solenoid is doing. If this is done shouldn't that allow the OP to start his engine. Cleaning those solenoids is great, but once they get like that the seem to return to a bad connection pretty quickly, that solenoid is not super expensive and a new one is likely to last another ten years or so. Just a thought.

[Morich]

Originally Posted by tim myers

Did not see this mentioned, but if you wanted to verify that the issue is with the solenoid not engaging or bad contacts, could the OP use a jumper cable to jump across the solenoid as in connect to the house side of the solenoid and also the chassis side of the solenoid, since this is all the solenoid is doing. If this is done shouldn't that allow the OP to start his engine. Cleaning those solenoids is great, but once they get like that the seem to return to a bad connection pretty quickly, that solenoid is not super expensive and a new one is likely to last another ten years or so. Just a thought.

Yes, I also feel cleaning the contacts on something that costs less than $20 is not my best choice. I used to do it when I was starving but getting that pressed metal pulled apart and then sqeezed back together was not something I trusted too far if it got wet!

Testing of the solenoid can be pretty simple if we can get in to reach it. One way is to do some jumper work.
If we have power on one big side lug, touching a strap from that side to the center small lug will operate the solenoid. That small lug needs power to go through the coild and to the ground which is the metal case and mounting screw on the three post type. It doesn't care if that power is coming from coach, chassis or even a sperate battery like jumping from a car.
Give it power and the contacts should close.
If we start with no power on the other big lug and power shows when we operate the solenoid, that is all it is expected to do!

Some of you older guys may remember when starter solenoids were mounted up higher in the engine area where we could jump out and short around the solenoid when it got bad? Pretty much the same solenoid! If the solenoid is bad and won't send power through the contacts to the starter, we could use an old set of pliers to jump around the contacts and move on down the road!

Sometimes we get too concerned with looking at how difficult and complex a solenoid sounds. It really is as simple as a switch, only it operates when we send power to it, rather than when we flip it by hand!
And like any switch on the wall, all it can do is pass power through or stop it!