marlincolby

I recently purchased a 2016 Super Crew Cab 4x4 F150 with the 3.31 rear end. It did not have a tow package, however all the wiring harnesses and tow/sport mode on the transmission were there. If I read all the specs correctly, I can still pull 8900 lbs and the payload is 1650. I elected to install an aftermarket class IV trailer hitch, and a Tekonsha 90160 Primus IQ Electronic Brake Control. Since this is not the factory brake controller, I understand the truck instrumentation will not show any data for TBC. I used a Curt 51437 Brake Control Wiring Harness (only the Ford end fit the Ford connector. The other end I cut off and spliced the wires together with the Tekonsha pigtail) and the Curt 56307 Vehicle to trailer connector, which plugged into the factory tow harness under the spare tire, and included the 7 pin tow plug receptical. At this time, all the pins in the 7 pin tow connector work, except the positive accessory (or tow battery charger). The trailer brakes also work ok. From doing some research, I believe I just need to buy and install the 8L8T-14B192-AA and 6E5T-14A94-BA fuse and relay, into fuse slots 9 & 21. However, when I look into those fuse slots, there appears to already be one pin sticking up in the fuse slot, and there didn't appear to be any contacts in the relay slot. Has anyone else made this modification of adding the fuse and relay to get the tow battery charger line to work, or have any other recommendations? I'm hoping once I buy and install the fuse and relay, all well work normally, but I question the single pin sticking up in the fuse spot, and wonder if this circuit does in fact exist since everything else did.