Where is the over drive solenoid on a 1996 ford ranger?

The overdrive solenoid on a 1996 Ford Ranger isn't a single, easily identifiable component like a large, separate solenoid. Instead, it's part of the transmission's valve body. You won't find a separate, externally-mounted solenoid labeled "Overdrive."

To access it, you'll need to remove the transmission. Then, you'll open the valve body and find the solenoid *within* the valve body assembly. There might be multiple solenoids inside, and identifying the overdrive solenoid specifically requires a wiring diagram and/or a shop manual specific to your transmission (e.g., A4LD, 4R44E, 4R55E, depending on your Ranger's engine and options).

In short: You can't just visually locate it. Transmission removal and disassembly are required. This is a significant repair job best left to a qualified transmission mechanic or someone experienced with automatic transmission repair.