Just went to wally world and picked up a 4 pin to 7 rv pin adapter.

Looks like this:

http://www.trailerdepotofsarasota.co...adapter-p-1245

I am using a friends trailer for all of 4 hours to haul something from the store to my house. The directions for this thing are plain shitty. Can I just plug and play....or WTF do I do with these other wires???? He has a very simple one axle trailer which isnt even equipped with an electronic brake. I just want to make sure that if I just plug this adapter into my jeep and the other end into his trailer I'm not going to damage something. I really do not want to mount this bracket onto my jeep either, can I just let it hand and make sure it doesnt hit the ground?

Thanks in advance as always.

Which entity has the 7 pin harness and which has the four pin?

Answer would look like this:
Jeep = x pins
Trailer = y pins

If all you want is to have the normal lights and such then you are good to go with no need to hook up the other wires.