63- headlights won't work

[jonzcustomshop]

After a brutal week of changing auto transmissions on the 63 3 times (the one constant was a "good" converter that I didn't know was bad), now the headlights wont work-- they did when I parked it 6 years ago with the bad trans.....
the running lights in the hood, dash lights, and taillights all turn on, just not the headlights--they are still plugged in at the core support---

What should I check, or look for??