Batteries not charging

[Dhall0070]

OK. Thanks for helping in advance..so. Batteries aren't charging from converter.
So 2019 3211 MOntana.
What I have done.
Took cover off fyese/ breaker area. Checked with multi meter. It'sputting out 13.34 vts. So i hit the little wizard button and it jumped to 14 vlts.
So I trace the wire to the red key swith. It's in the on position. I pull it out and check with multi meter both sides 14 vlts.
So next I trace the wire in the the battery compartment.
At this point the wire comes into a small red box. It's showing 14 vlts. The other red wire coming off goes up to the pump for the auto legs. 14 volts there.
Now. On the other side of this little red junction is 3 wires one possible 4 gauge that jumps over to another junction little red box. This is where I loose the 14 vlts. Now it's showing that the batteries are pretty much dead.
So I charge the batteries with a battery charger. The hold voltage but are not taking charge from converter.

Obviously the converter is working. All my lights work and it's pushing charge to the 4 gauge red wire at junction box.
So this is where I'm confused. Why isn't it charging the batteries..

I have no ideal what the other wires go to. Except the fact they have fuses. Again checked both sides of fuse with multi meter fuses good.

I can get pictures if that will help. Just not right now cause it's pouring raining lol.
Again.
Converter good
Red key switch is in and good.
Power to the front by the batteries in junction box then nothing to batteries.

[Daryles]

Carl wrote the Perfect 12vdc troubleshooting flow chart:
https://www.montanaowners.com/forums...ad.php?t=86323

You are definitely on the right track. If you have voltage on one side of those red self-resetting circuit breakers (#1 & 2) but not on the other, it is bad.
Replace it with Blue Sea or Bussmann one.
BTW #2 is 50A. #1 is 30A.

[Carl n Susan]

You found the problem. That last red plastic capped self-resetting circuit breaker is toast if there is 12+V on one side and zero Volts on the other. Replace it.

[Dhall0070]

Thanks. So much.

I'll try to find the replacements as suggested.

[Dhall0070]

OK so looked up both blue sea and bussman one. I can't find one that looks like what I have. What am I missing?

Thanks

[Carl n Susan]

Any RV shop, along with Walmart, Amazon, E-Trailer, have an exact replacement. It looks like this for a 50 amp. That is quick and dirty way to get you going.

Google 12V 50 amp self-resetting circuit breaker.


A better solution is to replace with an 80 amp breaker. Here is a link to an 80 amp Bussman self-resetting CB. Amazon seems to be down right now but they have them too.
https://www.waytekwire.com/product/e...-surface-mount