seems odd to me that they would all go out. like max said, not having a good ground would explain that. like max said, it could be broken or pinched wires. check the wires around the ball and make sure that they did not get pinched when makin a tight turn or something. you can also get one of those testers and isolate where the problem is - truck vs trailer. wally world or uhaul has them or you could use a volt meter. like max suggested, make sure a good ground is available cause without a good ground, no lights.
jd