Where is the modulator located on a 93 Ford Explorer?

The modulator on a 1993 Ford Explorer is part of the transmission. It's not a standalone unit you'll find easily accessible under the hood. It's *inside* the transmission case itself. Therefore, you won't be able to just "see" it or easily access it without removing the transmission.

The modulator's job is to adjust shift points based on throttle position and vacuum. If you're having transmission problems, you'd likely need a mechanic to diagnose whether the modulator is the cause, and even then, it's frequently more cost-effective to address the entire transmission issue rather than just replacing a modulator.