When I pull the switch for the headlights, the driver side headlight does not turn on, the park lamp/turn signal does. When it first did this, I could tap the headlight & it turned on, but not anymore. When I hit the bright switch, all 4 headlights work fine, when I turn it off the low beam does not light. Bad connection or some other isuue? I haven't checked/cleaned the connections yet. Was looking for some advice first. I've got a fuel pressure issue that is higher on my list of things to do. Any help would be greatly appriciated. Thanks.

It could be the bulb... yes it makes me sound naive but thats what i would check first... its more common in newer cars but my 79 elco the low beam didnt work but the high did, replaced the bulb and had a good day... but not everything is that easy... like my current taillight problems

Check the ground screws on the core support. I am experiencing similar issues right now as well...
KFD

Your headlight bulb is bad (high beam/low beam) on the low beam side. Replace with a new one.

It could also be the connector to the headlamp. They get corroded over time and don"t make good connections.
A little cleaning with a pencil eraser should fix this. Clean both the metal blades on the bulb and the quick connects in the wire pigtails (a small piece of 600 grit sand paper will work but be gentle). A little bulb grease after it is all done will help slow the corrosion.

Ron