Tail Light Problem, odd one this is. Options

[amilleri]

So I've had this problem for a while, not quite sure what is causing it at the moment, but... My tail lights currently do not work, the running lights only. Brake and reverse lights work. I changed the rear harness in the trunk that goes to the tails and have checked all fuses, the front marker lights work as well. I've also noticed that the rear defroster doesn't work, but that may be an unrelated issue. Anyone got any ideas here for this one?

[amilleri]

Ok update for the few questions you guys had and to explain a little better.

My brake lights and reverse lights work. The running marker lights.. do not... I have checked both bulbs and fuses and swapped out the rear trunk harness. I will be doing the actual tail harnesses that hold the bulbs tomorrow. I will re-check the bulbs tomorrow as well, but I would find it odd that all of the rear marker lights to blow out at the same time.

Again the headlights work, fog lights work, high beams work, front marker lights on the fenders work, blinkers all the way around work, all brake lights work and reverse lights work. It is just the rear markers that are always on when the headlights are on that are not working.