No 12v power when boondockin

Huck Finn · 07-13-2021, 07:12 PM

I have a 2018 Chateau 30D. The exhaust fan was left on and ran the house batteries (2-12v). I connected to shore power for two days and still no power. I bought new batteries but still no power. I checked all ,the fuses which are good. All the 12 v lights work on shore power. Any suggestions as I am on the road?
Thanks

Popfla · 07-13-2021, 07:20 PM

Is the USE/STORE (or ON/OFF) switch in the USE or ON position?

DavidEM · 07-13-2021, 08:27 PM

You would think that the use/store was set correctly when the batteries first ran down. But maybe it was switched by mistake.

Do the 12V devices, lights, etc run ok on shore power which would be the case even if the use/store switch were set to store.

The use/store switch is the only thing that routinely causes this sort of thing. If it isn't the switch, then check the main fuse on the converter. Maybe it has blown. If nothing works on shore power check the main A/C breaker and the one to the converter. Does AC stuff work on shore power like the microwave?

David

The_Breeze · 07-13-2021, 08:35 PM

The Use/Store switch is the easier find/fix.

You may have a 100A breaker near the battery box/cage. If it's tripped, a yellow plastic flag will be extended. Push that flag back into position.

Beau388 · 07-13-2021, 08:35 PM

Quote:

Originally Posted by DavidEM

You would think that the use/store was set correctly when the batteries first ran down. But maybe it was switched by mistake.

Do the 12V devices, lights, etc run ok on shore power which would be the case even if the use/store switch were set to store.

The use/store switch is the only thing that routinely causes this sort of thing. If it isn't the switch, then check the main fuse on the converter. Maybe it has blown. If nothing works on shore power check the main A/C breaker and the one to the converter. Does AC stuff work on shore power like the microwave?

David

There is also a 50 amp resetable circuit breaker in the battery compartment for the battery cable going to the master power/ use - store latching relay. Mine is in the very inside if the house battery compartment and hidden by the rear battery. It does not have a test button but does have a red flag that is pushed-in to reset the CB.

Popfla · 07-13-2021, 09:21 PM

One more possibility - - when you replaced the house batteries, if you accidentally reversed the polarity, even for a second, the two 40 amp fuses in the converter may have blown, which is what they are there for.

Huck Finn · 07-13-2021, 11:37 PM

Yes I checked the use/store switch. All 12v lights etc work on shore power

Huck Finn · 07-13-2021, 11:58 PM

Everything works on shore power. All fuses checked okay. I pulled the use/ store switch and it appears okay. Still nothing on batteries alone.

RV_Envy · 07-14-2021, 12:04 AM

Ummm, might be time to see if an inverter could help?

**16ACE27** · 07-14-2021, 12:40 AM

Quote:

Originally Posted by RV_Envy

Ummm, might be time to see if an inverter could help?

How would an inverter, which creates 120 VAC from the house batteries, help the OP's problem?

**16ACE27** · 07-14-2021, 12:47 AM

Quote:

Originally Posted by Huck Finn

Everything works on shore power. All fuses checked okay. I pulled the use/ store switch and it appears okay. Still nothing on batteries alone.

The USE/STORE switch is just a remote operator for the battery disconnect relay. Do you hear a distinct "CLUNK" when you operate the switch in either direction? If not, the latching relay may not be operating. This can be caused by the tripped 50 amp DC breaker near your house batteries as mentioned above (looks like this but the flag/button may be different colors):

Or:

There is a small (5 amp) inline fuse for the control of the latching relay right at the latching relay - that may be blown which prevents the switch from operating the latching relay.

RV_Envy · 07-14-2021, 02:27 AM

Quote:

Originally Posted by 16ACE27

How would an inverter, which creates 120 VAC from the house batteries, help the OP's problem?

Ooops, my bad. Misunderstood the issue. Re-reading.

It’s gotta be a fuse. Guessing but thinking there is a fuse between shore power switch and battery, no? (30 amp fuse) ? I know it was checked and not many carry such a back up but I’d try switching it out anyway to be sure.

Jimbo56 · 07-14-2021, 11:14 AM

Mine has an additional 50A breaker up front by the chassis battery. I think it’s blue. When mine tripped nothing worked. Reset it and wala, all ok.

abjbrtd · 07-14-2021, 08:45 PM

Back to basics.
Have you checked the voltage on the new batteries?
With everything (shore power unplugged, generator, use/store switch) off, you should read MORE than 12vdc, hopefully about 12.5

Any autosupply should be happy to test them IN your mh

Huck Finn · 07-16-2021, 09:47 PM

I have been on the road for a couple of days. Just got back online.
It’s a 30amp rig. New batteries were tested. All fuses in the panel were removed and tested. The use/store switch has been checked only visually. Could the emergency start switch in the cab effect it? I could not locate any in-line fuses or breakers. Everything works on shore power.

**16ACE27** · 07-16-2021, 10:03 PM

Quote:

Originally Posted by Huck Finn

I have been on the road for a couple of days. Just got back online.
It’s a 30amp rig. New batteries were tested. All fuses in the panel were removed and tested. The use/store switch has been checked only visually.
How can you check the switch visually? It's a 2 position momentary switch that controls a latching relay (see post #11 above).

Could the emergency start switch in the cab effect it?
No

I could not locate any in-line fuses or breakers.
Get into, under behind and around your house battery area. Trace the positive side cables.

Everything works on shore power.

That's because your converter is supplying the 12 VDC to the DC buss.

abjbrtd · 07-16-2021, 11:14 PM

Quote:

Originally Posted by Huck Finn

I have been on the road for a couple of days. Just got back online.
It’s a 30amp rig. New batteries were tested. All fuses in the panel were removed and tested. The use/store switch has been checked only visually. Could the emergency start switch in the cab effect it? I could not locate any in-line fuses or breakers. Everything works on shore power.

Ok, progress

The next step in the trouble clearing process is checking the battery cables, they have to be clean, tight and hooked up correctly

if they aren't right you could have low, no or too high voltage.

Visually and physically check each connection, there are several, tighten if you can move any of them.

Now it's time for a volt meter, available at Walmart, any autosupply, Amazon etc. cost less than $20. Test for 12+ dc volts at these 2 point with the red (+) test probe, you'll have to find where the ground (-) cable from the battery attaches to the frame of your mh, should be inside or close to the battery box for the BLACK test probe.

Good luck

Jimbo56 · 07-17-2021, 11:24 AM

Quote:

Originally Posted by abjbrtd

Ok, progress

The next step in the trouble clearing process is checking the battery cables, they have to be clean, tight and hooked up correctly

if they aren't right you could have low, no or too high voltage.

Visually and physically check each connection, there are several, tighten if you can move any of them.

Now it's time for a volt meter, available at Walmart, any autosupply, Amazon etc. cost less than $20. Test for 12+ dc volts at these 2 point with the red (+) test probe, you'll have to find where the ground (-) cable from the battery attaches to the frame of your mh, should be inside or close to the battery box for the BLACK test probe.

Good luck

Refer to your picture. The breaker is in the tripped position isn’t it. To the OP. You have a 50 a breaker under the hood and another by the house batteries. Make sure they are not tripped.

sspilot · 07-21-2021, 08:48 PM

I had a very near situation. I checked fuses and did all the suggested remedies. I had given up after turning off all circuit breakers and checking all fuses.
Weird thing happened when I reser aii the circuit breaker’s….. everything started working as it should. No explanation, just a thought……

JIM SNYDER · 07-21-2021, 08:54 PM

A tripped breaker in the battery compartment is the likely problem.

On my THOR WINDSPORT 29M, I have been fooled twice by these breakers. They are small and often mounted in partially hidden places in the battery box. Additionally, when looking at these breakers from above (when standing outside looking in the dark battery box), the little 'thingie' that drops down when tripped is difficult to see from above. Check all of them closely, make sure they are all reset.

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