* Manual Transmission: A manual transmission Ranger has no transmission control solenoids. Shifting is entirely mechanical.
* Automatic Transmission: A 1991 Ranger with an automatic transmission uses a simpler hydraulic system. While it might have *shift solenoids* inside the transmission valve body, these aren't typically referred to as "transmission control solenoids" like in later electronically controlled units. They're internal to the transmission and not easily accessible without removing the transmission itself. There's no external solenoid you'd find easily under the hood or on the transmission pan.
To find any potential issues, you'd need to take the vehicle to a transmission specialist or a mechanic experienced in older Ford Rangers. They would diagnose problems through testing and likely inspection/repair of the internal components of the transmission's valve body. There isn't a specific "location" for a readily accessible external solenoid.
