Ok. Why would I have headlights, turn signals, brake lights, interior lights, but no marker lights and tail lights?

Bad ground?

fuse

No marker kights front and back?

Year? Front and back, or just either or?

I visually inspected the fuses, but did not remove any. They look ok, but which one would I pull that would involve the running lights? Yes, front and rear running lights are not working. Give me the locations of the grounds I should check. I thought I touched upon them all, but maybe not. (68 bird)

The marker lights ground in the housings, you'd have to have a bad ground at each for them to not work due to ground, I THINK, don't know for sure. Since none of them work front or back maybe the headlight switch or the wiring harness/switch connector, that's the part that is common to both front and rear. Juice goes to the headlight switch then on to the lights, the marker lights tee off right at the switch connector, one brown wire going to the front markers and one to the rears. Can't remember any fuses between the switch and the lamps front or rear, and if the headlights work the switch has power. Do the lamps come on when the headlights are on or when the switch is in park lights position or not at all?

Or maybe all the bulbs are burned out.

I replaced the headlight switch, but that did not help. The running lights do not come on at all, even with the headlights on. 2 of the tail light bulbs are brand new, and the turn signals light when activated. I inspected the plug for the headlight switch when I replaced the switch, it looked good. Since then I have tried to wiggle the wires coming from the plug with no luck. Here is what happened when they stopped working, the head lights were flickering when the post on the switch was touched. While wiggling the post, the marker lights went out. I figured the switch was bad and replaced it. The headlights are now fine, but the marker lights still do not light.

Sure sounds like a blown fuse to me. You need to pull them out to inspect the metal rod inside the glass tube. If burned, the fuse is toast.

OK, take the plug off the switch and check for continuity from the plug to the marker lights. If you have no continuity you know the problem is a break in the circuit. If you do have continuity check the pins at the switch for voltage. If you have voltage at the switch where the plug connects the marker lights and continuity from the switch to the marker light it has to be the bulb itself or ground. You could take the plug off the switch and apply a known 12 volt source to the marker light terminal in the plug and see if the lights activate.
You have power to the switch to light up the headlights. The same switch lights up the markers, if there is no juice from the switch to the harness plug, it has to be the switch. If you're getting juice out of the switch to the marker plug but no juice to the bulbs it has to be a break in the circuit. Strange to get a break in the front and the rear circuits at the same time though.

You won't know until you make some tests.

Oh yeah,
Turn signal lights are a different circuit than the tail/marker lights.

Ok, I will double check the fuses and give it a go at the switch and plug. Thanks guys.