Cut off battery switch for chassis

Actually, if the secondary charger he is using is not a "smart one" (read that not voltage controlled very well) it IS a good idea to disconnect the battery-- the engine and transmission computers are not helped by power spikes and possible 15+ VDC.

And, it using a "not smart" charger, be sure to monitor voltage. It is OK to equalize marginal batteries (assuming no dead cell!). But you do not want 15+ VDC for very long.

William B wrote:
Kind of simple, but turn one off and try to start the engine, if it starts then you have the wrong switch.

And the alternative test is to turn on some ceiling lights, unplug from shore power (or shut down the generator) and hit a switch. If the ceiling lights go out the switch is for the house batteries.

Unplugging shuts off the converter/charger feeding 12VDC to the house and getting a false non-disconnect indication.

Kind of simple, but turn one off and try to start the engine, if it starts then you have the wrong switch.

My rig has two switches, one is for the house batteries and the other is for the AUX or Boost start that connects the house and chassis batteries. Wouldn't your batteries normally be seperate from one another and the chassis battery isolated from the house if on shore power?

If you push the AUX or Boost switch, you should hear the relay click.
Post a photo, maybe we can tell that way.

ricelake922 wrote:
To Stuckin Tracy - I need to cut off the voltage to my chassis battery because the battery is not holding a good charge when plugged into shore power enough to turn over the engine. I am at a RV park currently and I am placing a trickle charge on the chassis battery to fully charge it and for that I need to use the disconnect for the chassis battery. I had an eco charger but it is not currently working.

If it helps any, I have a trickle charger hardwired into my chassis battery and plugged into an outlet inside the RV. When on shore power or when the generator is running, it keeps the chassis battery topped of and ready to crank. I only turn the main battery switches off when storing for the winter without being plugged into shore power.

With that said, one quick way I determined which switch turns off the chassis power....the auto steps are connected to the chassis battery on my rig. I turned off a switch and when the steps didn't retract, I figured I had the right one!

I, too, do not understand the issue here. There should be no need to turn off the chassis battery to charge it.

To Stuckin Tracy - I need to cut off the voltage to my chassis battery because the battery is not holding a good charge when plugged into shore power enough to turn over the engine. I am at a RV park currently and I am placing a trickle charge on the chassis battery to fully charge it and for that I need to use the disconnect for the chassis battery. I had an eco charger but it is not currently working.

Maybe I'm not understanding the reason for the question. Why do you need to use the cutoff switch? The only time I ever used mine on my Monaco was if it was going to be stored and not plugged in. Then I didn't want any parasitic drain on the batteries, but plugged into shore power there should be no need.

Without a volt meter, use a 12 volt light in a non-sunlight area. Put the light onto the battery terminals. The charge from the trickle charge will make the light bulb shine noticeably brighter.

A voltmeter is the best answer.