2019 Thor Miramar 35.2 Disconnect status

[CountryFolk19]

I'm still new to this RV but have found this main switch to be just a pain.
I have killed my batteries twice now ok maybe once I might be able to blame the kids on the second time while having shore power on.

While on shore power the batteries are not charging until the main momentary switch is pushed the red light next to this switch is always is on as soon as you connect to shore power so is useless as an indicator while connected to shore power.

I found the disconnect switch under the bed. Is there a way to attach a indicator light to this disconnect switch so I know it's in Store or Use mode so I don't have to disconnect the shore power and count how many times I push this momentary switch? or walk back to voltage display on the inverter pad and wait to see if its draining or not.

Is there any other way you found to provide an indication your in use mode before killing the batteries.

Yes I'm thinking of putting a manual disconnect on the batteries themselves but for other reasons.

[Judge]

Welcome..... you have a lot to learn! This site is full of knowledge and information so use it wisely grasshoper and you learn much.


The Use / Store switch connects or disconnects the house batteries. When the shore power is plugged in, the red light will always be on in most cases... even if the switch is in the "Store" position (batteries disconnected).

If the Use/Store switch is in "Store," your batteries are disconnected and won't be charged by the converter when on shore power or using the generator.

If you unplug shore power, the light will be on in the "Use" position and the light will be off in the "Store" position. So unplug the shore and make sure the red light is on and then plug back in so you know the batteries are connected and charging.

There are other ways to know as well. If you have the FireFly or Rapid Camp multiplex display panel that has the house and chassis voltage, you will be able to tell when the switch is in the "Use" posiiton because your battery voltage will be over 13v when it is charging. If you flip it to the "Store" position, you will see the voltage drop as you disconnect them from the converter.

If you don't have the FireFly / Rapid Camp display panel with the voltage readings, you can use a voltmeter or install a permanent voltmeter so you always have a visiual indication.

There are also posts on here where people rewired the light at the relay so it is only lit when the switch is in the "Use" position.

After having several years of RV'ing under my belt now with a couple different coaches, this is a non-issue for me... but I agree it is a lousy design.

[CountryFolk19]

That is exactly what I explained lots of hoops to figure out what state this disconnect is really in. Yes I've been doing all those tricks to make sure its in use BUT.

This model does not have a switch with Use or Store like a light switch its simply a push release switch (just like a push button that stays up it springs back) that activates the disconnect solenoid it is impossible to know what state this solenoid is in without hoops. You need to make sure you only push it in once after you connect to shore or you will kill the batteries.

Just looking to see if anyone tried to put a indicator light under the bed which I can see while standing at the main disconnect switch at the door to see exactly what the state of this disconnect solenoid is in.

[Pete'sMH]

I see SO many posts about problems related to the use/store switch that I really wonder why the manufacturers still use them. A simple mechanical disconnect seems cheaper, simpler and more effective. And I’ve rarely seen the dealers actually use them. They seem to just let the batteries run down then wheel up a jumper cart. On my last shopping trip my sales person said they idle the engines of their inventory after every test drive (like that’s a good thing!).

[cavie]

Originally Posted by Pete'sMH

I see SO many posts about problems related to the use/store switch that I really wonder why the manufacturers still use them. A simple mechanical disconnect seems cheaper, simpler and more effective. And I’ve rarely seen the dealers actually use them. They seem to just let the batteries run down then wheel up a jumper cart. On my last shopping trip my sales person said they idle the engines of their inventory after every test drive (like that’s a good thing!).

This ain't rocket science. If you know that the ceiling lights are 12 volts, as you should, a working ceiling light after you disconnect shore power should be enough to tell you that the battery is still connected. No in storage.

[Beau388]

Originally Posted by CountryFolk19

I'm still new to this RV but have found this main switch to be just a pain.
I have killed my batteries twice now ok maybe once I might be able to blame the kids on the second time while having shore power on.

While on shore power the batteries are not charging until the main momentary switch is pushed the red light next to this switch is always is on as soon as you connect to shore power so is useless as an indicator while connected to shore power.

I found the disconnect switch under the bed. Is there a way to attach a indicator light to this disconnect switch so I know it's in Store or Use mode so I don't have to disconnect the shore power and count how many times I push this momentary switch? or walk back to voltage display on the inverter pad and wait to see if its draining or not.

Is there any other way you found to provide an indication your in use mode before killing the batteries.

Yes I'm thinking of putting a manual disconnect on the batteries themselves but for other reasons.

I just look at the inverter display. If the voltage display is less than 12.8 volts, the batteries are not being charged. With my Xantrex Freedom Xi 2000, the inverter is always on when there is shore or generator power is on in the coach.

[paulwadley]

My digital touch pad rapid camp display goes blank when my disconnect is turned off and comes back on when I activate the disconnect switch.


Paul

[CountryFolk19]

My multiplex works great can turn on lights you cant tell anything from that especially if fully charged battery's.

The only thing I can use is the inverter control if it's less than 13.5v than its most likely in store mode. 13.5v it's in use mode and charging the batteries.

[Judge]

The Use / Store switch is a mommentary switch in many of the coaches but it is still a Use / Store switch.... press once and it us "Use" and orpess again it is "Store."

There is another easy way to tell if it is in the Use or Store mode while on shore power without unplugging. Turn the breaker off to you converter. If the lights and other 12v applicances go out, it was in the Store mode. If the lights stay on, it is in the Use mode and the batteries are connected.

Just remember to turn the breaker on so your batteries will charge when in the Use mode.

[Judge]

Originally Posted by CountryFolk19

My multiplex works great can turn on lights you cant tell anything from that especially if fully charged battery's.

The only thing I can use is the inverter control if it's less than 13.5v than its most likely in store mode. 13.5v it's in use mode and charging the batteries.

The converter will drop the voltage when the batteries are close to fully charged so you can't always go by your 13.5V. You batteries could be at 13.3V when the converter is topping them off. The house battery voltage would be less than 12.8V when they are disconnected and being discharged.

Use my method in the previsous post to determine it and tell your wife and kids not to touch the switch!

[lwmcguire]

Originally Posted by cavie

This ain't rocket science. If you know that the ceiling lights are 12 volts, as you should, a working ceiling light after you disconnect shore power should be enough to tell you that the battery is still connected. No in storage.

That is exactly what I do and have for years

I use the second set of ceiling lights for two reasons

The entry lights time out after punching in the code and opening the door

Turning on the house batteries then lights the front living room lights and you can see to enter and turn on additional lighting

Exiting you can disconnect the house batteries standing on the steps

If storing for a few days or weeks then lock the door and disconnect the chassis batteries

No dead batteries when returning

[CountryFolk19]

Judge, yes that works and I've done it.
For others that still don't understand this THOR model. The only way to use the lights as an indicator is to shut the circuit to the convert off. If the lights stay on the solenoid is in "use" position and if lights turn off its in "store" position as Judge said, again only talking about what happens when shore power is connected because everything is useable as soon as you connect the shore power cable, you don't have to push anything to get things working. you do not need to "what some are calling the use/store switch push it" but if you don't you will kill your battery over time due to the few things that use the battery side. Hoop number #3

So back to my question has anyone figured a way to attach an indicator light to the disconnect solenoid to determine it's position? I have not found the wiring of that solenoid yet so not sure if it is even possible.

[Bob Denman]

Since they've got you in good shape with that switch: I'll just say, "Welcome aboard!"

[Beau388]

Originally Posted by CountryFolk19

So back to my question has anyone figured a way to attach an indicator light to the disconnect solenoid to determine it's position? I have not found the wiring of that solenoid yet so not sure if it is even possible.

You could just put a volt meter near the switch or use a voltage gated indicator light (same as an alternator charging light).

[Judge]

Originally Posted by CountryFolk19

again only talking about what happens when shore power is connected because everything is useable as soon as you connect the shore power cable, you don't have to push anything to get things working.

So just to make sure everyone is clear....

If the reverse poalrity fuses are blown on the converter or the circuit breaker for the converter is in the off positon, you will not have any 12V when you plug into shore power if the Use / Store switch is in the "Store" mode (or your batteries are discharged). When the converter has power, you will always have 12V on shore / generator power... even with dead batteries or in the Store mode.


If you want to change the wiring on your light, read this post and it will tell you one way to do it.... the search function is your friend.

https://www.thorforums.com/forums/f2...%94-21257.html

[16ACE27]

Originally Posted by CountryFolk19

Judge, yes that works and I've done it.
For others that still don't understand this THOR model. The only way to use the lights as an indicator is to shut the circuit to the convert off. If the lights stay on the solenoid is in "use" position and if lights turn off its in "store" position as Judge said, again only talking about what happens when shore power is connected because everything is useable as soon as you connect the shore power cable, you don't have to push anything to get things working. you do not need to "what some are calling the use/store switch push it" but if you don't you will kill your battery over time due to the few things that use the battery side. Hoop number #3

So back to my question has anyone figured a way to attach an indicator light to the disconnect solenoid to determine it's position? I have not found the wiring of that solenoid yet so not sure if it is even possible.

Yes, it has been done. There is a thread from last year as I recall where they changed the wiring connections between the converter and latching relay essentially permanently tieing together the converter and house batteries on one side and the DC load buss on the other side so the light only lite if the DC buss had power by closing the latching relay. Unfortunately my search foo is not strong enough to find that thread. Maybe someone else can remember more details on it?

[Judge]

Originally Posted by 16ACE27

Yes, it has been done. There is a thread from last year as I recall where they changed the wiring connections between the converter and latching relay essentially permanently tieing together the converter and house batteries on one side and the DC load buss on the other side so the light only lite if the DC buss had power by closing the latching relay. Unfortunately my search foo is not strong enough to find that thread. Maybe someone else can remember more details on it?

I had already put a link to that thread in my previous post.....

[16ACE27]

Originally Posted by Judge

I had already put a link to that thread in my previous post.....

Sorry, I skimmed right over that link. Yep, that was the proposed solution I was thinking of.

[CountryFolk19]

Unless I missed something on that thread it did not have a solution I'll go back and read it again see if I missed something.

[16ACE27]

Originally Posted by CountryFolk19

Unless I missed something on that thread it did not have a solution I'll go back and read it again see if I missed something.

Post # 30:

Originally Posted by Jdb

I figured this out, and am very happy with the solution!

I moved the converter’s positive output from the 12V fuse block to the power in side of the latching relay. I added a length of 4 gauge wire to extend to the latching relay.

This has everything working as I think it should. The Use/Store switch light is on only when the relay is latched - regardless of 120VAC connected or not. When the relay is unlatched the light is off. Also now, when 120VAC is connected, I can use the Use/Store switch to disconnect all 12VDC consumption - yet still have battery charging working. So, whenever I have 120VAC connected the batteries are charging.

I’m not getting any unexpected battery drain, or other issues. My monitor shows what I expected.

The four pics below show my meter (temporary install) monitoring the coach batteries:
Pic 1 is 12VDC only with relay unlatched
Pic 2 is 12VDC only with relay latched and cabin lights on
Pic 3 is 120VAC with relay unlatched (charging working)
Pic 4 is 120VAC with relay latched (charging working)

Dave