Trailer Wiring

New member, hopefully someone can help me. I recently purchased a camper. its a restored 1967 steury pop up. and when I went to plug in the 4 flat trailer connector to my 2011 Tacoma none of the lights worked on the trailer. now I've hooked my truck to a different trailer just to be sure and it works fine. and we have hooked the camper up to 2 different vehicles and everything worked perfectly. we checked the ground and it was in less than perfect condition so we drilled a new ground, sanded it clean, and screwed it tight. still nothing. very confused and a little frustrated. the truck didn't come with a factory tow package, so ive wired in a Hopkins 46365 taillight converter http://www.hopkinstowingsolutions.c...g-harnesses/?year=2011&make=TOYOTA&model=1492 . I don't know if anything on this harness might cause it to not work with this trailer, it being a 67 and all. ive used up all of the minimal knowledge I have on this type of thing and have not succeeded. so I hope someone here can point me in the right direction. thanks in advance!