Sounds like mistake on hooking up wiring on your 7-way connector... My Ford has a legend printed right on the case which blade runs which lights etc... Could be a ground issue as well...
You can also go to ETRAILER.COM as they they are the masters for all things trailers... You can match up colors probably by looking up your make of truck.
My 2010 truck also has separate fuses for each of these trailer connectors - I have three fuse panels on my truck Under hood, behind glove box and on passenger side kick panel...
ANother trick I do is I carry a 7-way connector test adapter. If this work then there is no problem with the truck side. has come in handy a few times.

Just my thoughts
Roy Ken