ATF: Landmark - No 12v power when disconnected from shore power

I just replaced 2 12 v batteries with 2 6v batteries wired serially. I also replaced 50 amp breaker with 80 amp. all works fine until I disconnect from shore power. The only 12v power I have is to the landing gear. The 2 6v batteries are wired together + to -. The other + is wired to the 80 amp switch. The other - has a white 600v cable to a connector panel. I'm not sure if this is ground.

Hi Jim-Evie,

When you're plugged into shore power, your Power Converter is supplying 12V DC to the fuse box, and to the batteries to keep them charged. When you disconnect, you're relying on the battery power getting to the fuse box. It appears to not be getting there.

Your last statement about not being sure if the battery negative terminal is connected to ground is somewhat troubling. But if the landing gear still work, perhaps it is ground.

The positive terminal goes to the 80 amp switch? / breaker? You didn't say which 50 amp breaker you replaced with the 80. Usually, people change the hydraulics breaker from 50 to 80. So if that's what you've done, it sounds like you've bypassed the rest of the 12V mini-circuit breakers, including the one that connects the batteries to the Power Converter and Fuse Box.

The row of 12V mini-circuit breakers has a copper buss bar joining all the breakers. The battery positive cable is usually connected to the first breaker on the row of breakers, so that the copper buss bar distributes that power to the other breakers. Wires on the other side of each breaker carry power to the various devices.

I've attached a picture of a typical setup. Your layout may not be exactly the same.

Thanks for the reply Dan. I did replace the 50 amp hydraulic breaker with the 80 amp. I do have a battery disconnect switch between the 80 amp breaker and the copper bus. I didn't change anything on the copper bus as it worked fine with the 50 amp breaker and the old batteries. The white cable I referred to is the ground. My unit is a 2013 land mark.
It does sound like I've bypassed the 12 v mini breakers. I don't understand why this happened just by replacing the hydraulic breaker. Any help would be much appreciated. I do have a picture but can't figure how to include in this reply.

Jim-Evie, click on Reply, after the "Quick Reply" box pops up, at the top of the box you will see some symbols. Hover your cursor over the third from the right till "Insert Image" pops up then click on that. Then follow the instructions.

Peace
Dave

Thanks for the quick reply Dan. Yes the breaker I replaced is the hydraulic breaker. Decided to upgrade from a 50 to an 80 amp. Also since my batteries were marginal I replaced two 12 v with two 6v. The white cable referred to above is the ground. It sounds like by doing this I somehow bypassed the rest of the 12v circuits. I'm puzzled how this could happen since the 50 to 80 amp replacement is cut and dry as is the serial config of the two 6v batteries. Any suggestions on how to include the remaining 12 v circuits?

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Here's my diagram Dan..

Jim-Evie said:

Thanks for the reply Dan. I did replace the 50 amp hydraulic breaker with the 80 amp. I do have a battery disconnect switch between the 80 amp breaker and the copper bus. I didn't change anything on the copper bus as it worked fine with the 50 amp breaker and the old batteries. The white cable I referred to is the ground. My unit is a 2013 land mark.
It does sound like I've bypassed the 12 v mini breakers. I don't understand why this happened just by replacing the hydraulic breaker. Any help would be much appreciated. I do have a picture but can't figure how to include in this reply.

Click to expand...

Jim,

Normally, the 50 or 80 amp hydraulic breaker would be pulling power from the buss bar at the breakers, not directly from the battery, sitting in front of the battery cutoff switch.

Take some voltage readings at the row of 12V circuit breakers. With shore power connected, and battery cutoff OFF, you should read between 13.2 and 13.6 V DC. If not, no power is getting from the Power Converter to the buss bar. In that case, look for a breaker with a teeny-tiny reset button as pictured below. See if the voltage reading is normal after pressing the reset.

If you are getting 13.2 - 13.6 V, turn off shore power and turn on the battery cutoff. Take readings at the buss bar again. You should be getting 12.6V or so from the battery to the buss bar.

We also have a 12V Block Diagram and Diagnostic Guide that includes some troubleshooting info that may help. Here's a link to that folder.

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The square 80 amp breaker you've installed close to the batteries is supplying 80 amps to the entire buss bar. What did you do with the original 50 amp breaker on the buss bar that feeds power to the hydraulics?

Also, is the cable from the negative post on the battery attached to the same place as used by the factory? It looks like it's attached to the ground buss along with other ground wires.

It looks like the 80 amp breaker is the new main breaker. Looks like your red wire from the battery is going to the 80 amp breaker then the the breaker buss.
It should go the the battery cut off switch. then continue to the breaker buss.
Although what you have should still work you still have the original hydraulic pump breaker in place so that negates any benefit of having the replacement breaker.
Check the side of each breaker. One will have a tiny reset button. That is a reset for the main, push it.

Peace
Dave

looking at your picture looks like you have it all right now. Like cookie said if you have a weak breaker on your hydraulic system you might need to still replace it.
https://manuals.heartlandowners.org..._Buss_Bar/Heartland/Buss_Bar_for_LM-BH-BC.pdf

I'm trying to get fancy like Dan and Jim and add text to my pictures, but looks like I need a lot more practice. :/

perhaps in fooling with the batteries you may have inadvertantly touched/ crossed polarity and blew the fuses on the converter?

Thanks Dave and Dan..problem solved. The breaker on the buss bar with the reset button had tripped. Reset and it's good to go. All 12v circuits working when disconnected from shore power.. Thanks again..