Troubleshooting wiring problems is never fun. Troubleshooting trailer wiring is the worst. Trailer wiring may be simple, but most of the time the troubleshooting is happening on the side of the road. If you're having problems with your trailer lights, or you anticipate some trailer wiring issues, you might want to check out this helpful troubleshooting tool. We tested it to see if it could make your towing life easier.