Electric steps only retract with ignition turned on

I had the exact situation you describe. Check all of your electrical connections at the steps for corrosion. Those connectors live in a very hostile environment and your coach has been around long enough for corrosion to work its way into the connections. In my case, the connections for the step on/off switch circuit were really, really bad. A little work with a tiny round file and some dielectric grease made it work good as new.