Here's a few notes I've collected over the years in case I ever have to buy a step motor. These are copied from various posts on rv.net. Maybe one of these part numbers will work for you.
Fred
Kwikee step motor replacement – 86-95 Taurus LF window motor
NAPA BK665-1395
AutoZone Dorman 742-206 Check last digit may be 5 or 10
also see dormanproducts.com
Ford part E9SB6323394AB ford 87-88 tbird 87-88 cougar 88-93 lincon contenintal
Dorman 742-211 This works with my motor assembly 9504
The Actual Motors are Identical Left to Right. It is the Transmission that is different. These Motors were used in Ford, GM and Chrysler Vehicles and can be found at pretty much any Auto Wreckers or Pick a Part Type place used and Any Auto Parts Store Brand New!
A 1986-1995 Ford Taurus left front window lift motor matched my motor. NAPA part # BK655-1395 $63.99 I ordered my motor from Auto-Zone Manufactured by Dorman part# 742-206. This has a lifetime Warranty and was $49.99.
Just replaced my 25 series Kwikee step motor with a Dorman 742-277 window lift motor for a 1986 Ford Taurus driver side window lift motor. They said the Taurus had a high torqe motor which is why the number ends with 277 meaning high torqe. My steps zip in and out with this motor application. It was a special order item but only took one day for them to get it to my local AutoZone store. I also noticed AutoZone had rebuild kits for Dorman window lift gear boxes (plastic gears) in the Help section of the store.