I have no power to the OBD2 port and the speedometer is going on and off. I'm thinking I have an electrical short.
From the symptoms you describe, it would appear that the problem you are experiencing is indeed electrical in nature. As electrical problems are often times difficult to diagnose, I would recommend having a professional technician, such as one from YourMechanic, look over the vehicle’s electrical system, to determine the exact cause of the your speedometer issue. From this diagnostic, they will also be able to make the necessary repairs to resolve the issue.