Need help with a new switch.

Hi guys, I could use your expertise. I have an old automatic pool cover, kept in storage for 30+ years, in good condition, and worked well last fall when I found it in storage and installed it. However, I left it out in winter, thinking it was waterproof, and now I can only get it to open or close by manually switching the red and black wires back and forth. I can't get my head around how I would build a switch or panel that could bypass the rest of what I believe to be a damaged apparatus. Details in pictures.

Level of electrical experience: Not much, but parents are coming to visit this weekend who are competent.

Thank you in advance, as you can understand, parts seem to be impossible to come by.

Details by order of pictures:
1 The entire apparatus extends from the pool motor, I am looking to replace it and with your help build a manual switch if possible from the box with wire that comes from the motor.
2 Pool Motor.
3 The piece I believe went bad. Had water in this spring when I opened it, the damage is from me. Perhaps it was waterproof 30 years ago.

4 Wire orientation to extend the cover. When I plug into power it will work.

5 Orientation to retract the cover. When I plug into power it will work.
6 Schematics

es.