The passenger side mirror turn blinker failed, rendering the old light ineffective. I attempted to replace both indicator lights with compatible LEDs, and the driver's side works fine, but the passenger's side remains ineffective. There are no visibly damaged components to the electrical leads or wires, either at the mirror or at the pigtail cluster under the hood, and none of the car's fuses are out. I tested the passenger's side connection with the working driver's side light, and it didn't work on the passenger's side. Very likely a draw somewhere, but an inscrutable problem that seemingly arose for no reason.