Good Morning,
I'm new to the site, and want to thank you for the opportunity to ask my question, and for your consideration in answering. I have just picked up a 1997 F350 Superduty with a dump body. The vehicle had a round 6pin trailer plug (for lights only) added by previous owner. I purchased a Tekonsha Primus controller and controller wiring kit for the truck. I found the factory connector under the dash, center of vehicle. Everything in the front went well (I think). What I can't find is the blue wire in the main harness to the rear of the vehicle. All information I am finding states Blue,...makes sense. I'm not seeing it, did the color change on some specific year? All of the wires in the main harness to the rear of the vehicle seem awfully "light" for trailer connections except one. I have included pictures of a 4 pin round connector at the rear of the frame with heavy gauge wires inside the loom, none of which are blue. I honestly haven't tested them yet to see if these are what I should be connecting too for a 7pin trailer plug with brake and aux pins. Curious to know if anyone else has run into this? I may me overlooking something very simple. I truly appreciate any advice that you can offer. Thank you for your time.