No DC Power at all

[patandly]

I just purchased a 2023 Grand Design Momentum 336m. After it's maiden voyage and keeping it at my house (on shore power) for a couple days I took it to park in the storage facility. At that time I was able to lower all the stands for storage. Before leaving I removed the DC Shutoff key.

Several days later I come back to retrieve something and there is no power at all. Thinking the battery might be dead I connected it to my truck and let it run for a bit (I think that charges the batteryright?). Still no DC Power.

I thought maybe I'd start the generator, but apparently you need DC from the battery to start the generator.

I checked the inside fuses and circuit breakers. Nothing obvious there.

The running lights did work when I had it plugged in.

Not sure what to do next with this. Any ideas?

If I wanted to take it somewhere to troubleshoot, is there a manual procedure to raise the legs?

Oh... and I should tell you... I'm a total newbie at this.

Thanks in advance for any insights you might have.

[bridgway]

I know this is a stupid question but did you put the shut off key back in and tun on the DC? Also, even with the DC turned off with the key, there will be parasitic drains from various sensors. plugging in your tow vehicle will supply some power but very little. it would take many hours to make a dent. best bet it to test batteries to see if they are dead. connect a good battery to provide power with jumper cables then try to start the generator. it will take 6 to 8 hours to get a decent charge on the batteries. they won't be full but should be a good start. if you did kill the batteries, just know if they are lead acid they will never be 100% again.
Hope this helps,
Bria

[TedS]

That's the key question I was going to ask.

[acoleman43]

The main disconnect is the disconnect for the DC on your main distribution panel. I would think the electric jacks/legs would be connected directly to the battery. If this is the case, and your jakcs/legs don't work, you likely have a dead battery. I would get a multimeter and test the voltage.

When you store your trailer, remove the battery, bring it home and connect to a trickle charger. When you're ready to take the trailer out of storage, just bring the battery with you, connect the battery and you will be in good shape.

If you need to get the trailer someplace else but have a dead battery, Another connect jumper cables to the trailer battery from your vehicle and start the generator that way (same way you would jump start a vehicle). Those generators need about 450 CCA to start. Even a 1.0L, 3 cylinder Geo Metro has a battery with 450 CCA....so your vehicle should be able to supply that much energy to start up the generator.

Once the generator is started (assuming the disconnect key is not removed) you SHOULD have both AC and DC power to do what you need.

[Jlawles2]

Even if you plug in the TV to try and charge the house battery in the camper most likely you will need to have the key inserted and turned on.

Best way to bring the house battery up is not through the 7 way in the truck, but to use jumper cables between the house battery and truck batteries as this will provide you with the most current without possibly blowing the fuse on the 12V+ in the 7 way.

[patandly]

Thanks for the responses. Yea, I definitely had the key in. I'll try giving it a jump and starting the generator.

If the battery IS completely drained, it seems like a defect. Given the battery was working when I parked... I took out the key... and it's dead when I come back... it seems like a defect. I've literally only had the unit a couple of weeks and I bought it new.

[howson]

Thanks for the responses. Yea, I definitely had the key in. I'll try giving it a jump and starting the generator.

If the battery IS completely drained, it seems like a defect. Given the battery was working when I parked... I took out the key... and it's dead when I come back... it seems like a defect. I've literally only had the unit a couple of weeks and I bought it new.

Forgive the bluntness, but no, it's not a defective battery or system in your RV. Unfortunately the "Battery Disconnect Switch" doesn't do what it's name implies--it does not completely disconnect the battery from systems that will drain it. Consult your owner's manual and in it is the advice to disconnect the negative cable from the battery for "long term" storage. Long term is not defined, but with a lead-acid battery anything more than a week will likely result in a dead battery.

You're not the first and definitely won't be the last that's been misled by the erroneously named "battery disconnect switch".

Are you familiar with schematics and know how to read them? If so I'll post a general diagram that shows how the 12V system is wired.

Howard

[Lonestar]

howson

Just thinking. With all the problems and misunderstandings about the battery disconnect switch, discussed on this and other forums, we would probably be a lot better off if GD left this accessory off the trailers. I seems to cause more problems than it solves.

[TedS]

Lonestar I agree. A switch that disconnects only non-power consuming devices is of little use.

[howson]

howson

Just thinking. With all the problems and misunderstandings about the battery disconnect switch, discussed on this and other forums, we would probably be a lot better off if GD left this accessory off the trailers. I seems to cause more problems than it solves.

Believe me, I think all of the moderators have at one time or another made the suggestion. I don't know for sure, but suspect RVIA mandates the switch. Again, speculation, but when the switch was first installed it probably did cut off all power, then over the years the requirement was amended so critical safety items were always powered...and here we are today with a ridiculous mandated requirement of little value (that actually just causes confusion).

[Cate&Rob]

howson Howard is correct. RVIA mandates the switch . . . and then requires that some circuits must bypass the switch. All RV manufacturers are obligated to follow these requirements to obtain the RVIA Inspection label that all RV purchasers pay extra for.

Rob

[patandly]

Are you familiar with schematics and know how to read them? If so I'll post a general diagram that shows how the 12V system is wired.

Howard

Yes, please post the schematic (I have a degree in electrical engineering ;-)

[howson]

Yes, please post the schematic (I have a degree in electrical engineering ;-)

Below is what I found on my '19 315RLTS. Note that the battery disconnect switch (BDS) can be open and the WFCO converter will provide 12vDC power to the trailer (assuming the RV is plugged into shore power or other 120vAC source). Also note with the BDS open that the WFCO converter does not charge the battery.

The majority of the regulars here leave the BDS engaged ("on", which means the key can not be removed) and never touch it--ever.

There's also many of us that have installed a second cutoff switch that is truly a 100% cutoff, removing the requirement to disconnect the battery. (For those in very cold climates or for trailers that will sit for a long time, say >6 months, removing the battery and taking it home to facilitate putting a battery tender on it every month or so might be the best strategy.)

Welcome to RV'ing. There's a lot to learn! We've all been there and done that, so don't hesitate to ask more questions. If you haven't read the Welcome Letter yet, please check it out, too, as there's lots of tips and tricks on how to get the most your time here on the forum.

Howard

[JBill9694]

On raising (and lowering the jacks) and assuming the jacks are hydraulic: For the landing jacks, there should be a socket on the top of the curbside jack for a hex bit. Use an electric drill to raise or lower the jacks. One person can do this fairly easy.

For the stabilizing jacks, same hex bit and drill on top of the hydraulic pump (there may be a sticker or label covering the socket. The jacks are then operated using the black knobs above the curbside propane tank (on my unit). This takes two people.

[Jomani]

Like others have said, the factory battery disconnect switch is pretty much worthless. I created a video while trying to figure out exactly how it worked on my Reflection - link below. The good news (at least on my rig) is that the 12v supply from the tow vehicle connects directly to the battery and does not go through the disconnect switch. If the battery isn’t completely shot, you can bring it back to life by plugging in the tow vehicle - very limited amperage of course.

https://youtu.be/VoBHzAFX6pk