For some reason, when my parking lights are on, my third brake light illuminates. Anyone know what causes this? 2 Days ago I replaced my s4 tail lights with s5's, but I haven't had a problem untill today. I double checked the wiring and everything seems to be normal. My stop light does come on telling me there is a problem, but only when the parking lights are on.

 

There is probably a wrong type bulb in one of the non-third brake light sockets.