When I start my corsica and turn the headlights on they will not light and the dash lights go out and the radio loses power. My power door locks will not work and the dome light will not work. There are a couple of times when everything works fine but most often not. When I start the car and the radio comes on, if I open the drivers door, the radio goes off, the headlights will go out and the dash lights will not light. The blower motor runs fine.
I'd have to check battery and connections. Also, fusible links stud. The headlamp switch, for the headlamps only, gets voltage from fusible link. When you turn on the switch, the yellow wire goes hot and carries the voltage to the dimmer switch. The dimmer carries voltage to high or low beam.