My starter motor is good, I can jump the solenoid and start my truck. Why isn't it working from the switch which was working before I put a new starter motor on?
It sounds as though you have either a faulty ignition switch or a break in your excitor cable somewhere (the small wire that goes live when you turn the key).
I had the exact same issue on my Volkswagen Bora and traced it back to the wire, around 3 inches from the point it connects to the starter. It made a tight bend back on itself and the heat of the engine had caused it to go brittle, loose it's insulation, corrode and snap. Thankfully it was a very easy fix.
Obviously is the ignition switch is at fault this wire will never be made live so this should also be checked.
It would be helpful to know the make and year of your car incase there are specific peculiarities (such as an engine immobiliser) to consider.