My dad has a 2010 Jeep Commander that I am helping him sort issues out with.
As I understand, there are two brake light bulbs per housing, and each is a double filament bulb so that when the headlights are on they are at low brightness and when the brake is depressed they are high brightness.
The third tail light works fine.
The top bulb on LH and RH assembly works when the brake pedal is depressed, but not the bottom bulbs on each assembly.
When the brake light is not depressed but the headlights are on, the low light filaments in both RH brake bulbs work, but nothing lights up on the left hand assembly.
In addition, the reverse lights on both LH and RH assemblies do not work.
I replaced all 6 bulbs today with no change. What gives?