Trailer Lights Not Working After Installing Trailer Wiring Harness # 118412 on a 2009 Toyota RAV4

Question:

I followed all instruction of video to install T- One. But, none of lights on trailer works. My 2009 RAV4 all light still working. I go through it over and over again. Trailer light still not working. Try other trailers and not work at all. let me know how i can find out the problem.

asked by: Helen

Expert Reply:

The first thing I would check is the fuse that came with the Tow Ready Custom Fit Vehicle Wiring, # 118412. If it is not inserted all of the way or is blown, the converter will not work. Make sure the power wire for the converter is attached to the positive battery terminal via the in line fuse holder and fuse. No other 12 volt connection should be used. Make sure the white ground wire is attached to a bare metal surface.

On the 2009 Toyota RAV4, there are 2 sets of connectors behind the tail lights. Connect the T-one harness to those that are closer to the vehicle taillights.

With everything installed correctly, you can test the wiring harness to determine if it is malfunctioning. Using a circuit tester like # PTW2993, test the wires going into the converter. If the signals are correct going in then you can move on. If they are not correct, then there is a wiring problem ahead of the converter.

Next check the wires coming out of the converter. If the functions are correct going in but not correct coming out of the converter, then something is wrong with the converter and it will need to be replaced. If the signals are correct going in and coming out then something is wrong with the trailer wiring. But since you have tried more than one trailer, it is unlikely that all of the trailers have a wiring problem.

expert reply by: Michael H