Someone added a trailer brake controller some years ago, but it has always worked fine. The last time we drove the truck is a couple days ago. We hit a few bumps and the lights flickered. Hit a few more and the car shut off. We looked inside and the ground wire going from the negative post was melted down, and the negative terminal was split in half. Now when we got a new terminal and ground wire we started having this problem with the other ground wire.