House Batteries not working?

D.E.Bishop wrote:

MDKMDK wrote:
When you post up a question about your rig, it's a good idea to post the year/make/model as well. Helps the troubleshooters.

In most class C/A motorhomes, the power step runs off the chassis battery.
Also, in most motorhomes, the shore power and generator will "light up" the coach without the batteries, so that's why it works when either of those two conditions are met.
Try this. There's a switch to enable/disable your coach batteries, sometimes located just inside the side entry door beside the inside step well. Check to see if that's in the "enabled" position. There may be a little green light on when it's in the enabled position.
Have a look, and post up your results.

MDKMDK's reply is very good except for the part about the chassis battery running the steps in "most" C/A's. If wired correctly, that is not true. Winnebago wires them according to the diagram in Kwikee Manual #888, so did Fleetwood.

The fact that the OP installed new batteries and the steps are now working indicates both dead batteries and that perhaps the steps are not wired correctly. It could also mean that someone modified the wiring.

To answers one of the OP's questions, yes the converter converts AC power to DC power but if you are on battery power the converter is not in the equation at all. As long as you have new batteries, either look up the owners manual and check for a battery disconnect switch. Odds are that if you post the Brand, Model and year of your rig, someone here will have the same rig and can answer your question.

Good luck.

My class A 2016 Sunstar (Winnebago) 26HE steps ran off the chassis battery, and that's the way it was wired at the factory. It's even described as such in the manual. Section 6-6 Electrical - see the section that starts - Chassis Battery....

From the 2016 Sunstar 26HE Owner's Manual......

""ELECTRICAL SYSTEM –
HOUSE 12-VOLT DC
The DC voltage system consists of the chassis
battery, the 12-volt house batteries, and the 12-
volt power converter.
Converter
See “Power Center.”
Chassis Battery
The chassis battery is used to operate the
engine starter and automotive accessories and
controls found on the instrument panel. The
electric step is also connected to the chassis
battery.
See your chassis manual for further
information on chassis batteries and chassis
electrical system.
House Batteries
House batteries are “deep-cycle” type
batteries specially designed for recreational
vehicle use. They will provide longer lasting
power than standard automotive starting batteries
and will withstand the frequent drain-andrecharge
cycles that occur under the demanding
conditions of a camping outing.
The house batteries supply power to 12-volt
equipment located in the living area of the
motorhome. This includes the following 12-volt
powered components (if equipped): interior 12-
volt lighting, range exhaust fan, propane furnace
fan, fresh water pump, systems monitor panel,
refrigerator, roof vent fans, slideout room
systems, and 120-volt electrical generator starter.
The house batteries can also provide
emergency power to start the engine if the chassis
battery is discharged. (See “Battery Boost
Switch” in Section 3 - Driving Your Motorhome).
House batteries are automatically charged by
the chassis alternator while the engine is running.
HOUSE/COACH BATTERY
DISCONNECT SWITCH
(COACH BATT)
The House/Coach Battery Disconnect switch
lets you disconnect the house batteries from the
12-volt system of your coach during storage
periods to avoid battery drain by electrical items
that are hooked directly to the house batteries,
such as clock displays and radio memories, etc.
Always leave this switch connected while
using the coach.""

I would also point out that Winnebago refers to "House" and "Coach" batteries in the last paragraph in the same sense, in other words that they are synonymous. The "Chassis" battery is the one that comes with the chassis (go figure?), from Ford, GM, Mercedes Benz etc..
That's how I've always referred to them, too. My house/coach batteries run the RV systems and the chassis battery starts the engine, and anything else the manufacturer chooses to run off of it. I suspect they do it that way to engage the automatic step retraction safety system, should you start your engine and put the vehicle in drive or reverse without first retracting your entry steps.

EDIT: I admit I generalized when I said "most" C/A power entry steps run off the chassis battery. I made an assumption based on personal experience, and at that point the OP hadn't revealed his year/make/model, so I generalized. My bad.

If I am in error I apologize, I should learn to never say never or always. I also assumed that the steps are Kwikee, there are others and I am not familiar with any of them.

I still say that the correct way for the step power to be wired is to the house battery. You must also note that I left out the control circuit that is connected to the chassis battery and is intended to signal the controller that the ignition is on and thereby tell the steps to retract.

In my rig the steps will not operate when the disconnect is in the off position. With the disconnect switch in the off position, there isn't any battery power going to the motor circuit in the controller unit. There is however power going to the control unit to close the steps when the ignition is on or in the start position.

My Bounder was wired that way too.

You see the chassis and the house batteries are both involved with operating the steps.

The motor circuit is fused for 20 amps and the control circuit is fused for 5 amps.

The drawing is located in figure 10 on page 10 and part of the Trouble Shooting section of Manual #888.