I have seem to notice that the marker lights intermittently shut off for a few minutes then come back on. does anyone else have this problem?

 

When my Firebirds have done this I usually re-seat the bulb and that takes care of it.

 

Is the full SET of marker lights doing this in unison, or is it just happening one light at a time?

 

yes the whole circuit. (marker lights, instrument lighting and dinger) tried looking for a fuse but couldn't find one

 

Spontaneous on-off-on-off behavior is not consistent with a fuse failure.
If a fuse goes, its gone until you replace it. Blown fuses don't just come back on.

On-off-on-off behavior impresses me as most likely a bad ground connection.

Trace the marker lights' circuit back to the relay that serves these lights.
A relay can play the on-off-on-off game on you, especially if the ground for the relay is decayed.

Inspect entire circuit for damage/deterioration.

A wiring diagram for your car will be helpful.