Recommended 7-Way Trailer Wiring to Replace Adapter from 4-Way Connector on 2003 Ford F-150

Published 03/09/2018

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Hook Probe Circuit Tester

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Dielectric Grease for Electrical Connectors, 2 oz.

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Question:

I have a 2017 Calico Livestock Trailer w/ a 7-blade connector. I have a 2003 F150 Ford Pickup with a 4-way flat wiring plug. I currently have an adapter, but I think it is the wrong one. When I plug the livestock trailer into the pickup plug, the turn signals do not work properly. For instance, one turn signal works and the other doesnt and/or when I turn on either turn signal both turn signal lights flash on the stock trailer as if I have the emergency flashers on. What is the correct adapter that I need for my vehicle and trailer? Thank you!

asked by: JL B

Expert Reply:

For your 2017 Calico Livestock Trailer, I recommend the Tekonsha Prodigy P3 # 90195 and wiring harness # 3035-P for your 2003 Ford F-150 with factory 4 way. Then I recommend the Ford Replacement OEM Tow Package Wiring Harness, 7-Way # 118242 which has the relays and fuses needed to activate your 7-way.

This will remove a possibly faulty adapter and allow you to use your factory wiring. If you want to keep your adapter and the wiring, I recommend you clean your connections with some sand paper, use some dielectric grease # 11755 and ensure you have a clean ground on your trailer that is bare metal to bare metal. Use a circuit tester like # PTW2993 to confirm wiring is functioning correctly. I've attached a wiring article to assist.

expert reply by: Jason S