Troubleshooting 2013 Ford F-150 Not Detecting Trailer After Installing OEM Trailer Brake Controller
Question:
I have a 2013 F150 STX. Installed OEM in the dash TBC to factory wire harness. Took to Ford and had computer flashed. Hook up to Trailer all lights work. But electric brake side will not connect up to truck. Had Trailer tested on friends trucks. Everything works on his. I did pull the trailer at 60mph and hit the manual slide and you can feel it grabbing some. But as far as dash. It says no trailer connected.
asked by: Rick
Helpful Expert Reply:
Since the dash on your 2013 Ford F-150 says no trailer connected, I would check that the 7-way connector on your truck does not have any corrosion or debris causing a connection issue, as this is a pretty common issue with your year of truck.
When you installed the OEM Trailer brake controller, did you also install the 12v power fuse # 21 and relay # 9? Without these installed you will also not get the trailer connected message.
The fuse and relay should be in the glove box of your truck, as Ford included them with every truck.
If you are still having an issue after checking these just let me know.
I included a link to a helpful article on wiring for you to take a look at.

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7 Way Trailer Connector Vehicle Tester
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