I just noticed that when my brake is depressed AND turn signal is on my trailer lights act like a 4 way blinking with the side that I'm suppossed to turn being much dimmer. In other words, both trailer lights go on when the brake is depressed (truck brake only on my rig), which is good But, when I turn a signal light on as well, both lights blink like I have the 4 ways on and the side turning, say I have the left blinker on, is much dimmer. Before this I would just sit in the truck and say is my lights working and do signals and whatever but this is the first time I actually walked back and looked myself, lol. ****ers! Good thing you can still see my truck lights I guess but could this problem be caused my me not hooking up the ground? btw, the trailer is brand new and high quality and I also bought a brand new electrical hook up for between the trailer and truck. The truck is a 92 chevy.