I can't beleive it would be mechanical since they closed so It has to be electrical. I have a '72 charger as well with hideaway headlights and so far no problem. Grab a meter and start testing the circuit.

‘72 Charger, 5.9 Magnum, Tremec 5 spd., Pro-Touring
‘14 Big Horn, Quad Cab, 4x4, 1500