Battery Disconnect Switch stuck to "On"

[GrimlocKing]

Hello all,

I have a 2018 Thor 31S. While trying to locate what I thought was a parasitic drain, I was inspecting my battery compartment to find that both of my parallel cables were extremely loose.

While tightening those connections, I inadvertently touched another piece of metal. I got a very small zap and then realized I still had the house batteries connected. I went to the disconnect switch and it isn't working. (It worked five minutes earlier)

All of the power in the house is working. I tried flipping the breaker in the battery compartment. I went to the disconnect switch to look for a fuse; I found one fuse that was fine.

I plugged in the coach to shore power so the batteries dont go dead. I used my multi meter and the charging is fine.

Is there another fuse or reset button am I missing somewhere so I can restore the disconnect switch?

Thanks in advance

[16ACE27]

Realize that the actual switch you touch is not the connect/disconnect switch/solenoid that actually does the connecting/disconnecting: it is a remote operation switch that controls a 2 position solenoid that actually makes/breaks the connection. I'm not familiar with the specifics of your coach, but generally the switch you touch momentarily applies power to one of two electromagnetic coils that physically move the switching part to either the OPEN or CLOSED position and leaves it there.

The fact that you can't get it to open tells me that the power going to the remote switch may be bad, or it could be the physical connect/disconnect switch, or the wiring in between to the OPEN electromagnetic coils.

I'd start with a voltmeter at the switch your finger pushes.

[TurnerFam]

probably, when you got 'zapped' you were simply making a connection between the positive and negative post of the batteries - which had nothing to do with whether the 'house' was connected, or disconnected.

because the 'house' items now work, you certainly have power coming thru the system as it should be.

because you can't now 'switch off' the house items may have to do with your 'zapping' moment - it may have temporarily set the solenoid/RV Custom Products device in a 'fixed' position. It works via an internal magnet - which creates a 'momentary' switch, to land at either one side, or the other, when you 'switch' the switch.

I would suggest that you disconnect the battery cables again, wait 30 seconds, then reattach. You may still seem some arcing - that's normal, even when you think you have all loads turned off.

you may then find that your switch and solenoid/RV Custom Products device is working correctly again.

try it, it can't hurt...

[Beau388]

There is a 50 amp circuit beaker in the rear of the battery compartment that protects the relay and 8 ga wire to the relay. There is also a 5 amp fuse around the relay to prevent the switch being held down too long and burning-out the switching solenoid for the relay.

[javelin]

I believe 16ACE27 has the correct focus on this one. If the latching relay is “on” and won’t release then I would suspect the fuse that powers the door switch that operates or releases the latching relay first. If you have the RV Custom BCC (black box in the engine bay driver side; usually mounted near the inside cap front); the fuses for controlling the coach and chassis latch relays are inside the BCC. If you have the BIRD or BIM systems then I don’t know where the control switch fuse is located. A call to Thor may provide the likely location though.

If it is not the latch relay control switch power fuse, it could be the latch relay itself has failed in the on position. Using a voltmeter to monitor the control pin(s) on the latch relay would confirm if the on/off switch signal is getting to the relay.

[Ghh]

Where is the Latching Relay located in a 2017 Ace 30.2. I can hear it activating but can’t locate it. I think it’s not working. I can hold the switch down in either the use or store position and everything works ok. But it want stay latched in either position.

[Beau388]

Originally Posted by Ghh

Where is the Latching Relay located in a 2017 Ace 30.2. I can hear it activating but can’t locate it. I think it’s not working. I can hold the switch down in either the use or store position and everything works ok. But it want stay latched in either position.

The relay is behind the power center under the bed. In my coach, it is in the forward corner.

[Ghh]

That’s great. I’m by myself and could hear it but couldn’t locate it because I was holding the switch down. Now all I have to do is get under the bed and see if I can find out what’s wrong. Looks like I have to take the mattress out and unscrew the plywood top to get underneath. I had one before that you just lifted it up because it was on hinges. Thanks again.

[16ACE27]

You don't need to hold the switch down. Once the relay moves it stays in that position until you energize it the other way. Hence the term "latching relay".

If you hear it moving, that part is working as designed. The only other failure would be if the contacts had failed so it never connected the batteries to the buss even when it was in that position.

[Beau388]

Originally Posted by 16ACE27

You don't need to hold the switch down. Once the relay moves it stays in that position until you energize it the other way. Hence the term "latching relay".

If you hear it moving, that part is working as designed. The only other failure would be if the contacts had failed so it never connected the batteries to the buss even when it was in that position.

The latching relay is mounted on the corner post in the upper right corner of the photo

[Ghh]

Well I opened up underneath the bed and I must admit, I’ve been spoiled by Winniebago and their quality of work. The plywood was partly screwed down and partly stapled down. Very poor quality assembly. I’m surprised the bed didn’t fall down. Anyway, enough of that. My question now is how do I determine if the latching relay is bad or the momentary switch. Everything works ok as long a# I hold the switch down ( in either use or store) but as soon as I release it things don’t work anymore. So I’m assuming the “Latch” isn’t latching. Any help would be appreciated. Thanks.

[Ghh]

To Beau 388. Didn’t see your response until I sent my last one. Yes, it does click when I put it in either position but when I release it it still doesn’t work. However, if I hold the switch down in either use or store and try the lights it works. But it stops working when I release. So I’m assuming the contacts are bad? But how does it get power if the contacts are bad.

[OldWEB]

A typical latching relay is intermittent duty, meaning it should not remain energized for long periods of time when operated. Some styles will melt or burn out (internally) due to the heat generated.

Try to post the relay info or at least a pic to determine the type of relay you have.

You did not say if it worked fine before or you bought it this way.

[Ghh]

Hope this picture gets to you.

[Ghh]

And yes, it worked fine when I bought it. When you out it in use it should be able to stay in the latched position as long as your using it.

[Ghh]

Another photo.

[OldWEB]

Next thing to try is, use a voltmeter across the coil terminals to see if the voltage does swap polarity when 'closing' and 'opening' the relay.

[Ghh]

Got it. I ordered a volt meter and should be here Monday. Appreciate your help. Thanks.

[OldWEB]

Here is info on the relay and its operation.
Intellitec Battery Disconnect
Good luck.

[OldWEB]

Originally Posted by Ghh

Got it. I ordered a volt meter and should be here Monday. Appreciate your help. Thanks.

A good voltmeter (and learning how to use it) is your friend when you have an RV!