Rear Light Failure warning light is on, horn is not functioning, and none of the interior lights work.
Hi there. If all of these issues happened at the same time I would start by checking the connection at the fuse box under the hood. The main battery terminals connection to the fuse box becomes loose and cause this. If that is fine then the problem may be in the dash. I would take some specialized tests and a digital voltage meter to locate the problem from there. You should enlist the help of a certified mechanic to do this electrical systems inspection, like one from YourMechanic.