Troubleshooting 2009 Ford Escape Trailer Wire Harness # 118551 Passenger Side Lights Not Working

Question:

I have recently installed a four point trailer harness on my 2009 Ford Escape. I have brake lights and turn signal on the drivers side. I do not have any lights on the passenger side and do not have parking lights on either side. I have been back through the wiring and it is correctly installed. The fuse is good and the ground wire is making contact. I tried it on two differnt trailers and have gotten the same results. What can I do now?

asked by: Matt B

Expert Reply:

I am sorry that you are having trouble with your trailer wiring harness. The next step you should take is to test the wiring at the trailer connector with no trailer attached. Use a circuit tester, item # PTW2993 if needed, and determine if all of the functions are present at the 4-Way connector. If all functions are working properly, then the trouble is on the trailer that you used to test the harness.

If you find that the wiring to the connector is not functioning properly, then you will need to test the wiring going into the converter box on the # 118551 wiring harness (see link). You should have left turn signal, right turn signal, brake signal, tail light signal and a 12-volt power wire going into the converter. If all of the functions going into the converter are correct and the functions exiting the converter are not, the converter has been shorted and will need to be replaced. If the converter is shorted, you should verify that all of the wiring on your trailer is correct before installing a new harness and plugging the trailer in.

If the functions entering the converter are not present and the vehicle taillights are still working properly, then there is likely something wrong with one of the connectors. In this case you could try unplugging the connectors and plugging them back in. Many times, this will solve the issue. If this does not work the harness will need to be replaced.

If the vehicle taillights are not working correctly you may need to check the turn signal and taillight fuses on the vehicle.

expert reply by: Robert G