Careful, it seems like ford has repurposed the old solenoid as a starter relay to energize the “real” solenoid on the starter (unless everywhere I looked is showing the wrong starter).

Careful, it seems like ford has repurposed the old solenoid as a starter relay to energize the “real” solenoid on the starter (unless everywhere I looked is showing the wrong starter).

2010 Explorerer’s wiring diagram agrees. There’s two wires going to the starter, one directly from the battery, and one from the engine compartment starter solenoid.
Edit: Confirmed the starter on my own 70’s Ford truck is a one wire affair, the switched 12 volts directly from the battery via the starter solenoid. There’s no separate “s” terminal.