Chassis Batteries

[TurnerFam]

Originally Posted by gmc

While Satellite would surprise me - steps do not... They must always extend when door opens - and always retract when ignition on (and door closed) - so can't be on a use/store switch with the coach batteries...
My steps are connected to chassis battery.

Not to be disagreeable, I hope... but while the steps 'seem' to be powered by the chassis batteries, it's not normally true - only CHASSIS vehicle items are powered by the chassis batteries, but NOT RV factory installed equipment(for the House, if you will)... the chassis as it comes from Freightliner, or Ford, have everything already wired for the vehicle to it's own chassis batteries. The manufacturer of the RV provides everything else, and all usually powered by the House battery bank. RV manufacturers default to this because the Chassis is the 'primary' power source, in order to crank the vehicle engine. Nothing else should draw from that or prohibit it's ability to crank and get you to where you are going. And, yes, some items, like the steps, MAY bypass the 12v Battery Cutoff switch in order to accommodate safety features, allowing them to work regardless.

The steps, along with other items, like the Leveling system, and even the Radio/Video systems, are powered by the House batteries, but may be TRIGGERED, in some situations, by the Ignition ON position, or the release of Air Brakes, etc., for safety purposes.

For instance, you can set the steps to stay out when you are parked, whether the screen door is open or not, but if you turn the ignition switch to ON, the steps will automatically retract, even if the door is still open, no matter how you have your door switch positioned - a safety feature. The wiring thru the ignition switch prompts this to happen, but the power for the steps is still from the House batteries.

The Leveling system has a similar feature - if you crank the engine and remove the Air Brakes, the Leveling system will sense this, and if the legs are still deployed it will alert you audibly and automatically retract them. The panel and the hydraulics are both powered by the House batteries, but the wiring between them and the Air Brakes provides for a safety override, in case you 'forget' to retract the legs.

[Pete'sMH]

Also not trying to be disagreeable, but... I disagree! Manufacturers deliberately power the steps from the coach battery because they are essential safety equipment. The steps need to work even if the coach is in store mode.