Most helpful critical review
Buy two and return the bad one
on October 13, 2014
First one we ordered kept the lights on all the time, even with vehicle off. Returned and got another, LED lights are on all the time even with vehicle off, but incandescent lights are OK. Of course every receiver plug with a light is LED. I'm guessing quality control is poor (50% defective IME) and the electronics are cheap, using high-leakage electronic relays.
In all, this was a waste of money; since the first one was bad, I had to use my Mustang to tow the trailer instead of my Mariner, which isn't much fun.
I wish I had done more research ahead of time, there's a factory wire in the rear bumper and Curt 55515 would probably have worked without running a power wire under the whole truck.