Where is the heater motor in a 93 Ford Ranger?

Your 93 should be identical to my 94. The blower motor is on the passenger side firewall. You can follow the coolant hoses from the engine right to it. It's very easy to reach, but I had to pull the box that holds the windshield washer fluid reservoir/radiator reservior to make enough room to slide it out. You'll need a 5/16 socket, a wire cutter and some small wire nuts. It took me about 30 minutes to do mine. That includes wiring mine backwards the first time. I knew that because the check engine light came on immediately. Once I reversed the wires, everything was fine. Good luck.