I was wondering about ours, see signature. Since you asked, thought I'd go figure it out.
It's powered by the House Battery, so the Battery Disconnect has to be ON. On ours, there's a Auto Reset Breaker, next to the Battery Isolator Solenoid, near the Master Cylinder under the Hood. Mounted right where the rear edge of the Hood closes. If you need a picture, I'll go take one. PM me a mobile number and I can text it to you.
To simply disconnect the Step to work on it, there's a four-wire connector very near the step itself.
My Standard Warning: BE VERY CAREFUL AROUND THIS THING! It moves faster than you'd think and it has TONS of Torque. Sucker can Hurt You.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB