The contacts are clean at the grounds. I'll pull them all apart and cleaned them up.
I'll switch the contacts and see if it affects the up the same way. No other solenoids to use that are the same design.
Last time i replaced the trim motor three years ago I pulled all the contacts, cleaned them and covered in dielectric grease to keep them from corroding. That kept the terminals clean, but I did have a corrosion issue with one of the wires inside the plastic terminal head.
I see I can get a used solenoid on ebay for $70. New one will run me $210 including shipping.

G.