my 96 pathfinder has a trailor harness tucked behind a lil access panel by
the jack in the rear cargo area

You need a wiring kit that taps into the tail light plugs (no cutting or
splicing required).  Whoever you got your hitch from should have them.

Although, when you say towbar, do you mean something you put on the front
to tow it behind another vehicle?  If you do tow it, you probably want to
put the 4WD lever in N, to save the transmission.

Try www.narva.com.au the US has a .com site as well

when my trailer lights gave me grief this is where I went for help I got
printable diags and it also helps to buy their connectors as well although
not neccisarry

worked for me

good luck