Connecting Battery Kills 12v System

[jfeltham]

Maybe this has been answered already, if so maybe someone can point me to the post.

We're on a 3 week cross country trip with the kids in a 31' Jayco travel trailer. Had our battery system give us some trouble today while entering New Mexico from Texas. At a rest stop for lunch, we noticed our refrigerator had stopped working on LP. Looked into it and discovered we had no 12v anywhere in camper.

Just got into the campground about an hour ago (in a heck of a thunder and lightning storm) and when we hooked up to 30 amp AC, I still had no 12v systems working. After fooling around and looking at it for over 2 hours, I discovered that if I disconnect my battery, my 12v systems work. Very strange to me.

The short of it is the following:
- Battery is fully charged (brand new last week).
- All fuses and breakers test good with multi-meter.
- I get 12v between the positive fuse holder near the battery terminal and frame.
- I have no 12v input into the converter from the battery leads at the rear of the converter.

Anyone ever run into something like this before?

PS...had to create a new login identity. On the road and I can't remember my sign in credentials...but I'm a regular here on RVnet. Best thing to come about since camping itself!

[98coachman]

BobsYourUncle wrote:
By any chance did you reverse polarity on the new battery?
That can really toss a wrench into your 12V system.

x2 sounds like you connected the new battery up backwards. Good luck,Bill

[BFL13]

"discovered that if I disconnect my battery, my 12v systems work. "

How exactly do you "disconnect"? That might help with this.

I am hoping you did not just get the wrong way for using the "battery disconnect switch", so when you think you "opened" it, you actually "closed" it, so now everything works!!! 🙂 (That would be something I would do when under stress, setting out.)

[BobsYourUncle]

By any chance did you reverse polarity on the new battery?
That can really toss a wrench into your 12V system.