trailer wiring, 89 pathfinder

[alecb415]

Im planning on setting up a trailer hitch on my 89 pathfinder(2 door, se, v6)
ive been looking into it. online i have found wiring harnesses for pretty cheap, however when i called for quote from a trailer install plaxe they said you need to install a tail light modulator, becuse my model doesnt run enough juice to power the second tail light set. im not really sure what a tail light modulator does.
Has anyone self installed a hitch and wiring harness ancan help me out? do i need the modular? what is a modulator? and do the kits for sale online come with one or not.

thank you.
Alevc

[mar1]

what kind of trailer? do you need power just for the lights at the back of it?

if yes, then the power coming to your trucks rear lights is enough.