Dale,
A prior owner had removed the automatic stairs on my MH, and when I found a NOS set for sale at a reasonable price I decided to put them back on. Luckily they had just pulled the plug out and zip tied it out of the way on the stairs end, but the door switch was not functioning and the wires were to short to put a new switch back in the same spot.
I had to drill a new hole about 6 inches lower in the door frame and then hook the 2 trigger wires to make the steps operate. I did wire in the new step plug in to the old wires since it was in much better shape than the original.
Hopefully you will be able to locate the wires both in the door frame and underneath in the step area.