Working on 74 model. Checking two other cars I know that when the key is turned to run position the headlamp relay closes. On the car we are working on, the relay does not close, but if we connect 12 volts directly to the coil it will close, so we know it is good. We have checked continuity on both limit switches and both seem to be fine. Looking at the schematic, it looks like the ignition switch supplies power to the relay coil. Can the ignition switch be to blame for head lights not closing?