Originally, this car had a simple brake light switch, but I guess they kept burning out, so they recalled the car and put in a brake light relay to better handle the load.
Since the brake system is pretty straightforward (battery, switch, relay, lights), there wasn’t much to check out. The switch checked out, so I took a closer look at the relay only to find that–hey!–it’s being held together with electrical tape.
And inside–ewww–it’s completely rusted. Time for a new one.