Where is the transmission modulator for a 93 Ford Aerostar?

The transmission modulator for a 1993 Ford Aerostar is located on the transmission itself. It's a small, usually vacuum-operated, device mounted on the passenger side of the transmission case, near where the transmission control cable connects. It's relatively easy to spot once you're looking at the transmission, but might require some maneuvering to access depending on the Aerostar's specific configuration.