Fuse for battery disconnect? Converter charger? Need help...

[SJ-Chris]

Hello all! I'm having a strange issue that I cannot seem to diagnose.
I have a 2006 Four Winds Chateau 31P Class C RV. I've owned it for 9 months now. I've got 3 new 12V deep cycle house batteries (all purchased 6 months ago). I have not had any issues lately regarding charging, batteries, etc. When the RV engine is on, the alternator is providing 14.1v on the house batteries. When I was plugged in to shore power, my WFCO converter (purchased 6 months ago) was charging the house batteries. When my Onan generator was on, the house batteries were getting charged and everything in the RV works (120v and 12v). Something changed over the last week.

I have a volt sensor connected to an app on the house batteries and I can see that they are fully charged (~12.9v) after a recent 5hr drive. I just put a volt meter on the house batteries and confirmed that there is ~12.9v on the batteries (engine off, not plugged in to shore power, and generator off).

Here's the issue... For some reason (when not connected to shore power) the Battery Disconnect switch is no longer working. When I am not connected to shore power and the generator is off, when I turn the Battery Disconnect switch 'On' nothing happens (...it used to work fine up to just one week ago). Now, nothing happens. And none of the 12v items in the RV (ie. lights, etc) work. I also notice that the Kwikee electric step does not move when I open/close the side door. If I turn on the generator (or plug into shore power), the Battery Disconnect switch seems to be overridden and all the 120v and 12v items in the RV work fine AND the electric step opens/closes perfectly anytime the side door is opened or closed.

I checked all the fuses in the RV house converter fuse box and they are all fine. Is there a separate fuse for the battery disconnect? I don't remember the electric step requiring the battery disconnect switch to be "on" in order for the electric step to work. How does your electric step work on your RV when the main battery disconnect is 'off'?

I also notice now that when I plug into shore power or turn on the generator, nothing changes on the house battery voltage (...Looks like they are NOT being charged). All of the 120v and 12v items on the RV work when plugged into shore power or the generator is on. The AC...the microwave...the electric side step all work when plugged into shore power or the generator is on.

Any thoughts on what I should check? Is there a fuse for the Battery Disconnect (and electric side step)? Could the fuse be under the driver side dashboard? (those seem to be more associated with the RV engine and dash and lights....).

It looks like there might be two independent problems...something wrong with the Battery Disconnect, and the converter charger doesn't seem to be working. Thoughts?

Your help is greatly appreciated!

-Chris

[Cydog15]

wa8yxm wrote:
First the switch in the photo is a common DPDT center off rocker with as couple jumpers To replace it go to an electronics store and get a DPDT center off (Will be labeled (On)off(on) switch.

RUn a jumper from top left to bottom right, and from top right to bottom left.

Hook up same as it is now You may need to turn it upside down.

BUT... Before you do that.....

REmove the two CENTER leads (Label them right and left)

Cycle the switch like 50 times both directions.

Re-connect and see if it works.

Did you see he found it was a resettable CB, short stop.

[wa8yxm]

First the switch in the photo is a common DPDT center off rocker with as couple jumpers To replace it go to an electronics store and get a DPDT center off (Will be labeled (On)off(on) switch.

RUn a jumper from top left to bottom right, and from top right to bottom left.

Hook up same as it is now You may need to turn it upside down.

BUT... Before you do that.....

REmove the two CENTER leads (Label them right and left)

Cycle the switch like 50 times both directions.

Re-connect and see if it works.

[Cydog15]

We used to call them Short Stops. When I look back through the good intended "internet experts" posts, I'm surprised nobody asked if you checked for a resetable circuit breaker.

[trailrider]

A simpler way to bypass is to stack the two big cables together on one stud and tighten the nut. No jumper wire needed. And by the way that's a nice over sized lug with a crappy crimp on that cable in the picture.

[SJ-Chris]

Hi All, I wanted to provide an update...

I was able to convince myself that the issue was that somehow the 12v from my battery bank was not getting to the battery disconnect solenoid (...along with it also not getting to the Battery Disconnect switch by my side entry door). Somehow the 12v power from my battery bank was not getting to the converter box area. Based on all the amazing feedback/suggestions from all of you, I was leaning towards some sort of fuse. I tried for a while to trace the wires back to my batteries but there were way too many wires in my converter box area for me to make much sense of it. I was also short on time as I needed to get the issue fixed within about 24hrs. After spending about 2 hours I decided to throw in the towel and bring it to my mechanic.

My mechanic was nice enough to jump right on it (...knowing I needed it back quickly). After spending 3 hours searching they finally found the culprit. Basically it was a 40a 12v inline circuit breaker/fuse (Type 1 cycling reset) that had gone bad. A $7 part. Once they replaced it, everything is once again working flawlessly in my RV. While I am happy to have it fixed, now that I see where it was (...right out in the open) I am a little surprised that it took my mechanic more than 30 minutes to find it. I'm still a bit of a newbie and I wasn't even aware that the items were fuses (...now I know). Had I known that, I would have focused more on them as the problem was really looking like it was an issue of a break of some sort (ie. fuse) in the line going from my battery bank to the battery disconnect solenoid and/or my converter box.

Here is the fuse:


Everything is now working. Thank you all for the assistance! Special thanks to Mandalay Parr. He invited me to call him for his assistance. I spoke with him a couple times and he was extremely knowledgeable and freely gave me his time and expertise. I learned a lot from him. Thanks!

RV.net is the best!
Chris

[dougrainer]

The VOLTAGE to activate the solenoid and TO the wall switch comes from the HOT side of the large post on the solenoid. So, NO VOLTAGE, your system will not work. period. Follow the hot side large wire to find where it is dead. Doug

[SJ-Chris]

Thanks all for your advise so far! Here is an update....

I checked all the fuses prior to posting my original message and they all look good. There are two that are on the solenoid (there is one on top and one on bottom). They were both good. There was another misc small inline fuse that I checked and it was fine. I have checked all the breakers and fuses in the converter box and all were good.

I just did some probing with a volt meter to see what I could learn. I was able to find 12.7 volts among all the dozens of wires by the junction box and solenoid (...to make sure my volt meter is working). I also checked the house batteries in their compartment to verify that they are good and got 12.9v.

Then I started measuring voltages around the solenoid and that's where things get a little strange.... I was expecting that the voltage on one of the thick wires going to the large solenoid bolts was going to have 12v on it and the other would have 0v (because afterall the solenoid is just a big switch...). So far were were assuming we have either a bad Battery Disconnect switch or a bad solenoid. BUT, I was surprised to find NO VOLTAGE on either of the large bolt posts of the solenoid! I then checked the voltage across the smaller bolts of the solenoid (...my understanding is that when the battery disconnect switch by my side entrance door is toggled it should put a voltage across these smaller posts to "turn on" or "turn off" the solenoid). There was zero voltage change when the battery disconnect switch was pressed 'on' or 'off' by my assistant. Hmmm.... Now I'm more confused!

I have heard from some research that there could be a 2nd battery disconnect switch in some RVs. I have never seen such a switch in my RV and I have poked around lots. I took a look at the house batteries to make sure their connections looked good and they look rock solid. I looked at the heavy gauge wiring underneath the battery compartment to see if somehow they got broken/cut and I didn't see anything unusual. Where are some locations that a 2nd disconnect switch could be? I have also heard some speak of an inline fuse on the heavy gauge battery wire (maybe as it travels to the converter box???). Is that common?

Let me know if you have any ideas for me to check. Thanks again for your help!!
Chris

[Matt_Colie]

Chris,

I have seldom seen so much good and accurate advice as you have here.

What has not been said is that thing is a magnetic locked contactor. It is like a big relay with built in magnets to hold it open or closed. The switch just provides a pulse to make it do what you want. Those pulses are supposed to be short. The contactors seen to be very reliable.

If someone or something held switch for much time at all, the fuse opened. I have seen this happen more than once.

For the short term, a hard jumper will work. Just be sure to remember to disconnect it in storage.

Matt

[road-runner]

That remote switch is simply a DPDT, center-off, momentary contact switch wired to supply one polarity in one of the "on" positions, and the reverse polarity in the other "on" position. To test the solenoid, just hook battery power to its coil terminals. One polarity turns the disconnect on, the other polarity turns the disconnect off. Easier than doing that, just hook a meter to the coil terminals while somebody works the wall switch. That should tell you if it's the wall switch or disconnect solenoid that's not working. It looks to me like that fuse on the solenoid might be for the power feed to the wall switch.

[ksg5000]

Have you checked the two fuses on the top of the intellitec battery disconnect solenoid?

[dougrainer]

See the orange 5 amp ATC fuse in your pic? There is ANOTHER fuse on the bottom side of that solenoid. They have 2- 5 amp ATC fuses and BOTH must be good for the system to operate. To bypass is simple. Use an 8 gauge wire and just connect the 2 large posts on that solenoid. Doug

[Mandalay_Parr]

Call me Chris.
I can help you over the phone.
I am a retired electrical troubleshooter.

[SJ-Chris]

Is this a viable short term work-around??? Assuming for a moment that I don't care about having a functioning Battery Disconnect switch by my side entry door, can I just use a properly gauged wire jumper across the two large terminals on this solenoid? If my understanding of how the battery disconnect switch works (providing just a temporary voltage to 'latch' this solenoid on/off) and how the solenoid works (effectively connecting or disconnecting the two thick cables on the large terminals) then it seems like if I wanted to bypass both of them and always have the batteries "on" then I could simply connect a properly sized jumper across the two large terminals. Right??? Please let me know if I am missing anything. There are other wires connected to this solenoid and I'll be honest, I am not sure what they all are or what they all do (...so maybe putting a jumper across the two large terminals would actually be a bad idea...)

Or is this solenoid more complex? Perhaps it is doing certain things to isolate the charge coming from the chassis alternator when simultaneously plugged into shore power (and the converter/charger is on)???

Thoughts from you experts??

Thanks!!
Chris

[SJ-Chris]

I continue to learn..... I was reading up more and here's what I learned...

The wall switch is in fact just a remote switch that goes to a house battery disconnect solenoid located under the rear bed near the converter. Here (I believe) is a photo of that in my 2006 Four Winds RV:


When I push the battery disconnect switch by my side entry door, I believe I used to hear a "Click" noise. I assume that was coming from this solenoid. Well....now when I push the battery disconnect switch by my side entry door I do not hear any sound at all. I suppose it could be a bad disconnect switch, OR it could be a bad solenoid. Can anyone recommend how I can easily check the solenoid to see if it is working properly?

I found a replacement solenoid here if needed:
https://www.amazon.com/INTELLITEC-0100055000-Battery-Disconnect-Relay/dp/B072N8NYN2

Thanks!
Chris