no lights/12volt

I had a similar problem. Mine turned out to be the wing nut on the ground battery post wouldn't stay tight.
Seems the threads on the battery stripped at the bottom. I put a washer under the wing nut and the problem was solved. It would disconnect and connect just sitting there. You would hear the carbon monoxide detector chirping.
This affected everything. Starting the generator, shore power, the steps.

raining and wind blowing me away will check and advise later. I cant thank you all enough as this is a learning curve my first MH . Redone the roof and put the extension ladder up against the rear moved it and yep wiped out the ladder. I am 6'4 inch and 300 lbs so I don't like stressing the ladder that came on it..while fixing the roof leaks . It rained hard all night and no leaks... The previous owner fought it also as it appeared he used everything on the planet to fix, got the heat gun and scrappers and took it done to original replace antenna and refrigerator vent and sewer vent, Used the roof tape with aluminum backing, then cool sealed the whole thing. NO LEAKS , now just figure out this wiring issue and replace water filters and we are ready to roll, also new breaks, and oil seals and air bags.. Tired of spending money for awhile ready to enjoy!

There should have been some type of power on the small posts when the switch was activated. Look in the battery control center for a blow fuse for the control.
Mine is fuse 19 a five amp.
Did you check for voltage on the battery disconnect? What was it?

yes sir I will certainly check for reset and circuit cuz I haven't found them yet, I have a magnum charger/invertor and is only a couple years old, original owner had a small fire on the electric cord roll up device and they replaced it all at dealership in Mississippi. I have the manual for it and fixing to get to reading now on finding a reset. YOU GUYS ARE GREAT , I used to ask my dad for help on this stuff but he just passed away and he was a mechanical engineer by trade and could fix anything...

In the BCC there are two post,each has a small circuit breaker.They are black, and easy to miss. Try the reset
I had the same problem when I changed my bats.

Chuck

Yes sir I installed but made a diagram and had a book and everything worked when I got back , I took a meter and have nothing on the 2 small post when we make the switch in the cabin at the relay. so I should have it narrowed down to a switch or relay... thanks all I can get it from here , I will do like all the mechanics just change parts till its fixed and save 85.00 an hour..

I guess my question is did you install your new batteries or were they installed by a professional...

Installing two 6VDC batteries wired in series which are in parallel to another set of 6VDC batteries wired in series can get mis-wired rather easy...

Roy Ken

Dou you have a voltmeter?
If you do locate the battery disconnect relay.
Connect the leads from the voltmeter to the small terminals.
Have a helper push the switch. Meter should read voltage.
Have the helper push switch the to the opposite position.
It should read opposite polarity from the first test.
This should identify whether the switch is bad or the relay.
Another test again using a volt meter is to test whether the relay contacts are made or not. Connect one lead of the voltmeter to ground and the other to the large battery side of relay. Read and document reading. Then move the lead to the other large post. The readings should be the same if the contacts are made.

embarrassed to say I don't know how , prior military so good at following instructions I watched a you tube video, and I think I know where that circuit is the chassis clicks when you switch it on the firewall and the other one doesn't, the intellitec battery disconnect switch for the coach feels different than the chassis, wonder if that board/switch is gone? Thank you for the help

Locate your battery control center. Test for open main fuse. Cycle the coach battery disconnect.
Check the inverter/charger, if equipped for a small white or red reset button.