Trailer wire prob...

[jskrours]

I have a small tag-a-long trailer. I added running lights to the sides and wheel-wells and for about a year it all worked fine. Then I started to have a short (I call it a short) in the system. The park lights will be dim and when I hit the brakes, the lights go even dimmer and after a few minutes the fuse blow. I always have to clean the connecter a few times and after I get lucky, they work for a short time and then a few months later I start all over again. Any help would be great...