Troubleshooting Factory 7-Way Trailer Connection on 2016 Ford Transit T350

Question:

Hi , o have a 2016 transt 350 with a trailer socket not working ,, fuse f 43 is ok and i replaced the box in the stepwell ..it was working fine until i plugged in a trailer that had a damaged cable which i found out when it was too late upto that it was working fine .. any idea where my problem could be

asked by: Daniel

Expert Reply:

Because you know that your trailer cable was damaged, you will want to check each fuse that has to do with towing. You will want to check F4, F9, F12, F31, F43 as you stated, F45. Also relay F3, R8.

After confirming these are good, you will want to use a circuit tester like # PTW2993 to test each function at the round factory harness just behind the connector. If you confirm the functions all work as intended behind the connector, then simply use # HM40975 or # C55774.

If the factory round harness behind the bumper trailer connector does not work, you will use the circuit tester to trace each wire probing every couple of feet to pursue a wire short.

If your vehicle lighting is working correctly, you can alternatively choose to use the Tekonsha OEM Replacement Vehicle Wiring Harness w Brake Controller Adapter - 7 Way Trailer Connector # 22116.