Modify Outside Air Step Wiring

By Barry and Cindy 1997 U270 36'

Modify outside air step wiring to allow step to retract when ignition is off

I also have modified outside step wiring to allow step to retract when ignition is off. I did it for security reasons and have used it several times. It prevents someone from stepping up to look in door window. And makes a parked Motorhome less inviting and secures the small storage behind the outside step when folded up. And in a confined parking situation, makes step less vulnerable to physical damage.

One may also want to install a 'kill' switch to prevent a quick engine start if ignition is jumpered. One could prevent battery current from reaching ignition switch via a 'kill' switch if a more secure situation warrants it.

The 3-way step air control valve on our 1997 U270 is powered when ignition is on. This 12 volt ignition power feeds through the magnetic door switch to retract step. With ignition on, if screen door or main door is opened, the magnetic door switch is opened, air valve de-energized and step will lower. When the 3-way air valve does not receive 12 volts, it feeds air pressure to air cylinder to force outside step open. When the 3-way air valve receives 12 volts, it feeds air pressure to the other side of air cylinder to force outside step closed. When ignition is off, the air valve is de-energized and step stays open, no matter what position magnetic door switch is in.

To retract step when ignition is off, supply 12 volts to magnet door switch to simulate that ignition is on. When screen or door is opened, magnet door switch will open to lower step so we don't fall on our face when leaving coach. Step will NOT change from open to close and back to open, etc. if front brake air tank is depleted.

In this situation, step can easily be physically moved to closed or open position and will stay in the position.


To modify outside step circuit, I found wire 'C11' leading to magnetic door switch. I mounted an inexpensive single pole double throw switch.

Switch does not have a center-off position. I cut wire 'C11".

I connected cut wire that goes to magnetic door switch to center pole of switch. I connected other side of cut 'C11' to one of the side poles of switch. I then connected a house battery hot wire to other side of switch. This circuit modification will not interfere with normal coach operation. It will be another small constant draw on the house battery when ignition is off and switch is in modified position.

Hope this help to explain how outside step works on our coach and is an aid for you to design a modification that works for your coach.

© Barry Brideau 2003-2017