I'm not very electrically inclined, but I know the basics. I HATE trailer lights, they work, they don't, one blinker works, one doesn't, etc. etc. Well here's my prob. The lights work, but one side wont blink or brake. I'm confident it's a Truck Side problem because the trailer is brand new, and because it does the same thing with my other trailer. This is a 7-way round connector. Anyone know where I should start to troubleshoot this?