That does sound like it's the issue.
The first two pics below are of the starting system. I broke on pic into two parts so they are more readable. I did overlap them so you can follow them.
Next, the ignition switch actuator rod itself may be out of adjustment as well. Here are directions for adjustment:
1990 Ford Truck F 150 2WD Pickup L6-300 4.9L
Vehicle Starting and Charging Sensors and Switches - Starting and Charging Ignition Switch Adjustments
Locking Pin Hole Location
see pic 3
1. ROTATE the ignition key back and forth to either side of lock, until a 1.98 mm (5/64-inch) drill bit can be inserted through the lockpin hole as far as possible (minimum 9.5mm (3/8 inch) ). The lock pin hole is located on the right of the switch next to the steering column tube.
2. Loosen the two ignition switch mounting nuts.
3. Turn the ignition to LOCK (feel for detent) and remove the ignition key.
4. Move the switch up and down along the column to locate the mid-position of rod lash. Tighten the two ignition switch mounting nuts (TOP NUT FIRST to minimize rod binding) to 4.51-7.34 N.M (40-65 in-lb).
5. Remove the drill bit from the ignition switch lockpin hole.
6. Plug in electrical connector and operate the lock cylinder to ensure the switch is positioned properly.
7. Confirm that all accessories are deactivated with ignition switch in OFF position, and that all accessories are operable in RUN position.
Let me know if that helps or if you have other questions.
Images (Click to enlarge)
Tuesday, September 8th, 2020 AT 3:06 PM