The Toyota RAV4 is a small sport utility vehicle designed to carry people to and from their destinations, but it's also able to tow a small trailer behind it. To do that, you need to have two things: a hitch installed on the rear of the vehicle, and a wiring harness that connects the RAV4's taillights to the taillights on the trailer. Installing one of these harnesses takes about 30 minutes to do, and it does not require any special tools.
Open up the back hatch and pull out the carpet and lower floor trim panel. Remove the plastic trim panel on the threshold of the door using the trim panel removal tool. Remove the two plastic access panels on the side panels with your fingers, then pull out the tail light access panels on the inside of the previous compartment with your fingers as well.
Unscrew the side panels from the floor using the Phillips-head screwdriver and a 3/8-inch ratchet and socket. Pull the panels back away from the sides by pulling on them sharply so that you can access the wiring. Lay out the trailer wiring harness so that the side with the red and green wire is on the passenger side of the cabin.
Unplug the driver side tail light wiring harness behind the interior panel. Install the T-connection from the trailer wiring harness between the two sides of the tail light wiring harness by clipping the harnesses together using your fingers. Repeat this process for the passenger side tail light.
Peel back the double-sided tape backing on the converter box on the passenger side of the wiring harness. Place the converter box inside of the trim panel. Unbolt one of the tail light bolts on the passenger side of the vehicle with the 3/8-inch ratchet and socket, then bolt the white wire from the tail light harness onto the tail light stud using the 3/8-inch ratchet and socket.
Push the interior panels back onto the sides of the vehicle and reinstall the mounting hardware with the 3/8-inch ratchet and socket and a Phillips-head screwdriver. Allow the trailer plug connection from the harness to lie loose and in the cavity underneath the floor panel you removed in Step One. Push the threshold panel back onto the floor and reinstall the floor panel by folding it back onto the floor.