headlights are not working . ground issue ? 1973 dart slant 6

67Dart273 said
At this point you are either down to a ground issue or the headlights are bad. To check that, pull out either lamp a little so you can access the connector, with the headlamp still connected. With the HL switch on, clip your meter ground to the battery neg. to start with and probe the connector. 1 of 2 will have power at a time and the other is ground, so this can be confusing.

67Dart273 said
You can use your meter and "ohm" the lamp. All three pins show continuity to each other on a good lamp

Headlight connectors again showed power at all three terminals . Headlamps showed continuity on all three pins . so, lamps appears to be good .

Grounding Issue ? - I am having trouble deciphering the wiring diagrams . The Ground wires that "Y" together at the firewall . i went ahead and cut them off and separated them because the ends looked corroded . They seam fine though after peeling back the jacket a bit on each one . one makes the sound for continuity from the bulkhead in both the high and low beam connectors . The other one does not make the sound with the meter on either high or low connector . Does that other wire go somewhere else ? i can't figure it out with the diagrams . I just get headaches .