I have a tag-a-long trailer and I only use it 6-8 times a year, but each time I hook it up, I always have to clean and fiddle with the wires. It has a short that I think is in the 7-prong connecter or it might be dirty. When I hook it up, the park lights are on but dim and when I hit the brakes then the lights go even dimmer and after a bit then the fuse blows. ANY HELP OUT THERE???