The scenario changes every other time, but right now, here is my situation (68 Bird):

My regular beam headlights will not come on at all. The brights do work though (all 4 are working when I switch the brights on).

Sometimes I get dash lights, sometimes I don't. My turn signals work most of the time. My gas gauge is not working.

I assume it is a ground somewhere, but I have not been able to locate the right one. I replaced all the dash cluster light bulbs, and have also just replaced the light switch. Could it be the dimmer switch shorting everything out? I bought one, but haven't hooked it up yet. Or is it just a ground somewhere?

By the way, all my tailights are working (blinkers and everything). This is getting frustrating!!!! Please help!

Sounds like you have several small problems. The headlight problem definitely could be the high/low switch. The dash light problem could be the dimmer part of the headlight switch. The gas gauge problem is often the ground and that is on the tank.
Jim

Update: I now have dash lights and turn signals. Still no fuel gauge or low beam lights. I can't figure it out. I wouldn't have done anything that would have knocked the ground loose on the tank.

I'm hoping that the lights are because of the dimmer switch. What is the easiest way to replace that? How do you get at it? Remove the kick panel then pull the carpet?

What grounds should be hooked up that would affect the lights?

Do the lights have any tie-in with the dash? By that I mean if something wasn't working on the dash (like my fuel gauge) would that affect the lights? Or vice versa?

silly, but...

did you check to see if the low beam filaments are burned out? Use an ohmmeter across inner and center tap to see if you have continuity or open (black/tan and black leads on bulb socket). Black is grounded to body.

Outer (High/Low) headlights have two different filaments, one for high, one for low, selected by dimmer switch. Inner (High) have only one filament. If ohmmeter test is good, check for clean contacts at dimmer switch.

Will do. What is the best way to get at the dimmer switch?

pull up the carpet.... loosen and pull back the kickpanel, pull the door-sill plate, and maybe even pull the plastic guard under the pedals. that should give you plenty of room.

you might want to use penetrating oil and a six point socket.... i think it's 1/4" bolts. i had to drill one of mine. (illinois)

Thanks for the info so far. Do the headlights have any correlation with the dash lights/gauges? If I don't have low beams, and I don't have fuel gauge, could that be ONE problem or is it definitely TWO problems???

Also, does the high beam indicator light (at the top of the gauge bezel) have to be connected for anything/everything to work? The ground wire that's back there connects through that as well.

Electrical Issues!

Electrical problems can even drive professional mechanics crazy. If I told you waht my lights do right now I'd get 15 different opinions as to what the problem is. Basically it's a process of elimination.

If I turn on the headlights all my lights work except the dash lights. Step on the brakes and the dash lights come on. Turn off the headlights and step on the brake and the dash lights come of as to all the exterior courteosy lights. All because the tail light housings are not completely tight. They are only finger tight as I have them loose for paint and body work.

Electrical ground problems are sometimes hard to diagnose as they produce mutliple symptoms.

The headlights and dash lights have one thing in common; the headlight/dash light dimmer switch. The dimmer part of this switch can cause intermittent dash light problems. This switch HAS to be grounded. Run a good gound to the back of the switch.
Your headlight problem is most likely one of two things; 1. bad connection on the back of the headlight or burned out filaments or 2. dimmer switch on the floor.

I had ALL of those mentioned problems right after I took the main dash out and replaced the vinyl. Once I reset ALL the screws to the dash, ensuring each screw was locking in to its intended target, the electric problems went away, like....immediately! There are a few dashboard screws that do infact ground several systems, though you'll never see that on a schematics diagram. Check all those dash screws, make sure they are linking up with the nutplates. Pardon the language, but make sure every hole has a screw in it, the right screw!

As mentioned, bad ground at the tailight housing caused problems. Electrial is fickle stuff. I would try a dimmer switch for the headlights and check the ground straps for the instrument panel.

Thanks to everyone that helped. A new dimmer switch solved the headlight problems. Also, I replaced the fuse for the gauges, and the fuel gauge came back to life. It was a trying process to get to that point though! I don't wish electrical problems on anybody!