Starting system
As I recall your North Face has a SOHC. Your 1999 model starter wiring should be similar to my 2000 wiring.
Energizing path:
Ignition switch > Fuse 24 (7.5A) in Central Junction Box >
Clutch Pedal Position Switch or Digital Transmission Range Sensor > Starter Motor Relay in Battery Junction Box > Ground
Power path:
Fuse 5 (50A) in Battery Junction Box > Starter Motor Relay in Battery Junction Box > Starter Motor Solenoid mounted on Starter > Ground
Battery path:
Battery > Starter Motor Solenoid > Starter Motor > Ground
I believe the older Explorers had a Starter Relay mounted on the inner fender well.