No DC power

[Fishinstreamers]

I have no DC power in spite of brand new 6 volt batteries x2 and completely replacing the converter in my 2016 3790rd. Battery shut off switch is on.

The stupid thing won't run the fridge, furnace, jacks or anything else unless plugged in to shore power or generator is on.

Just replaced the 75 Amp converter and it made no difference at all.
My battery panel says no charge but thats not true. Both batteries are fully charged on my separate charger.

What could possibly cause this?

Thanks

[jimcol]

Sounds like the battery shut off switch is in the wrong position. Many have complained that the wording is confusing. I'd switch it to off and see.

[Ram Montana High Country]

Originally Posted by jimcol

Sounds like the battery shut off switch is in the wrong position. Many have complained that the wording is confusing. I's switch it to off and see.

Or possible corroded contacts - the other thing I ran into was the ground to the frame was BAD - take it loose, grind it and reattach and then seal with battery sealer. - that was the devil to find.

[Creeker]

Would be a shame for all that expense and work just to be a simple thing as the battery cut off switch in the wrong position. If the red key will come out of the switch, you have it in the wrong position.

Switch could also be bad. Check voltage coming into switch vs. going out of switch.

[Carl n Susan]

It likely is not the disconnect switch as it does not cut off power to the jacks. The OP says the jacks don't work either.


With new batteries, I would suspect someone blew the reverse polarity fuses. But with a new converter too that doesn't seem likely either. Where I would look, and closely, is at the 12V flow from the battery to each of the 50 amp self resetting circuit breakers and on. I suspect one of them is bad.

[mhs4771]

And to make sure those 6V Bats are hooked up in Series

[Daryles]

No DC power. Shore power good.
Take a multimeter. On shore power, check each post of your 50A self resetting circuit breakers near your batteries. They should all read the same (about 12.4vdc).
Now remove shore power. Check them again.
Which ever one is NOT showing 12vdc on the post, it is bad. Replace it.

[Montana Man]

I fixed a friends that did the same thing. Turned out to be fuses in the converter. They blew when the battery was connected in reverse.

[Tom N OH]

My money is on the batteries being connected in parallel instead of series.

[Fishinstreamers]

I have checked the reverse battery connect fuses all pristine. The Battery disconnect switch has been checked in both positions. The Ground for the battery to the frame is clean and tight.
Will check the 50 amp self resetting circuit breakers and get back to you!

Battery #1 is Positive terminal to Black terminal wire, Negative terminal via pigtail to positive terminal on Battery #2. Negative Battery #2 terminal connected via white white to ground on Frame which is clean and tight.
Pretty sure thats the right way to do it.

[Fishinstreamers]

Originally Posted by Daryles

No DC power. Shore power good.
Take a multimeter. On shore power, check each post of your 50A self resetting circuit breakers near your batteries. They should all read the same (about 12.4vdc).
Now remove shore power. Check them again.
Which ever one is NOT showing 12vdc on the post, it is bad. Replace it.

I just did this readings as follows:

The self reset breaker visible on the right is 12.2 and 12.2 on shore power, then 12.2 and 12.2 with shore power off and batteries on.

The reset breaker that is hidden behind the battery box (why did they do that!) is 12.2 on the right pole and 0.00 on the left pole with shore power on and exactly the same with shore power off.
Not what I was expecting or hoping to see.

Battery #1 reads 6.0 V and Battery 2 reads 6.1 V just fyi

[mhs4771]

Looks like you found your problem.

[Fishinstreamers]

Originally Posted by mhs4771

Looks like you found your problem.

Are you saying the one that reads 0.00 is bad? That's not what I understood Daryles to be saying. ???? Or at least how I understood it.

Thanks!

[mhs4771]

A circuit breaker should have the same voltage on each terminal, when it trips you then get Zero on the load side.

[Fishinstreamers]

Thanks,
That makes sense but I was wondering what other electrical witchcraft was up because it was the same on shore power as battery power. But if that makes no difference then I certainly understand that! Thank you kindly!

Jim

[Daryles]

Originally Posted by Fishinstreamers

Are you saying the one that reads 0.00 is bad? That's not what I understood Daryles to be saying. ???? Or at least how I understood it.

Thanks!

Correct.
Paraphrasing here...

If it works on shore power, your conveter is good.
Power flows from the converter through the breakers to the load (systems) AND batteries (to charge them.

OFF shore power, the power flows from the batteries through the breakers to your systems.

Due to the way these thermal circuit breakers are made, they can work one way but NOT the other, much like a diode. I believe one of our members took one apart and found they are simply a bi-metalic switch.

Your normal circuit breaker pops open either/both ways

You can test it by bypassing the breaker with a jumper wire. BE DAMN CAREFUL!!!.

[Fishinstreamers]

Originally Posted by Daryles

Correct.
Paraphrasing here...

If it works on shore power, your conveter is good.
Power flows from the converter through the breakers to the load (systems) AND batteries (to charge them.

OFF shore power, the power flows from the batteries through the breakers to your systems.

Due to the way these thermal circuit breakers are made, they can work one way but NOT the other, much like a diode. I believe one of our members took one apart and found they are simply a bi-metalic switch.
our normal circuit breaker pops open either/both ways

You can test it by bypassing the breaker with a jumper wire. BE DAMN CAREFUL!!!.

I think I will test it with a bypass. But I will be careful.
Thank you to all who helped out!

[rohrmann]

Originally Posted by Daryles

Correct.
Paraphrasing here...


Due to the way these thermal circuit breakers are made, they can work one way but NOT the other, much like a diode. I believe one of our members took one apart and found they are simply a bi-metalic switch.

Your normal circuit breaker pops open either/both ways

You can test it by bypassing the breaker with a jumper wire. BE DAMN CAREFUL!!!.

The thermal breakers in these rigs work in both directions. When connected to shore power, the converter is producing 12 volts DC and some of that voltage is charging the batteries through the breaker. When not connected to shore power, that 12 volt DC power is traveling through the breaker from the batteries into the main panel. If the breaker gets hot enough from loading, it doesn't matter which way the power is flowing, it will open up the circuit. Once it cools down, it will close if it is an automatic breaker. If it's a manual reset breaker, it will have to be reset manually.

[govslug]

while we are on this subject....similar situation...found the battery was cooked...we keep it on shore power at the house so battery was baked out...I have a disconnect switch I want to install . Can I put it on the ground side of the battery ? The hot side will still have power coming into the battery , will this still cause my battery problems ?

[Tom N OH]

Before we answer your question, we need more information to give the proper answer. What is the ultimate goal in using thIs cutoff switch?