1998 trailer light connections

[frustrated dave]

I have a 1998 F-150 that did not come with the trailer tow package. I installed a wire harness that plugged into the trucks wire harness along the frame by the spare tire. This harness had a 4 wire flat plug which I connected to the trailer. None of the trailer lights work however. We hooked the trailer up to another 1998 F 150 with that had a tow package and the trailer lights all worked fine. I am at a loss as to what to try next.
Any help!!!!?????

[bigdad8214]

Get a test light and see if that plug has got power, I don't know right off had if it needs another fuse.....

[Colorado Osprey]

The trailer tow fuses may also be missing or removed.
There will be one for trailer running lights as well as one for right and one for left turn/brake light.