On my 1989 and 1993 F-150s the starter solenoid is mounted on the right "inner" fender about 6 or 8 inches "aft" of the battery. I suspect yours is there also.
On the Starter
the solenoid on that year ford starter is on top of the starter itself. that starter is used on a wide variety of ford products.
It is located in the engine compartment on the passengers side firewall. the solenoid is located under the hood
Right front fender wall
Find the positive battery terminal. Follow the thick cable from that terminal and it will lead to the starter solenoid.
The solenoid is on the starter.
The starter solenoid is mounted directly to the starter.
It's located on the side of the starter.
The starter solenoid is physically mounted on top of the starter motor itself.
The 1992 Ford Taurus starter solenoid is bolted onto the side of the starter itself. The starter is at the rear of the engine at the bell housing.
the solenoid is on the starter the relay is on the fight inner fender
The solenoid is attached to the starter. There is no relay.