Hello! My passenger side tail light is much dimmer than driver side on my 2012 Prius v. Any thoughts on why this is and what to do about it?
If incandescent, probably a bad connection. Try swapping the two bulbs side to side and see if the problem a) moves (then bad bulb) or b) stays on the same side (bad connection) or c) fixes itself (you managed to redo the connection when moving them).
The combo (tail and brake) 2-element bulbs can also cause weird issues when one element breaks and shorts to the other. On a v-2 I'd expect those are not LED. You can't rule out the bulb without replacing it. (or swapping)
They also can cause odd problems if the ground wire is loose or corroded. As mentioned, first remove the bulb and inspect the socket. The bulb might just be loose in the socket.
