When i plug the cell phone charger in the cigarette lighter everything is fine until i turn the headlights on... Long story short... i can't use the lighter plug at night, no voltage, zero, nada.... Is this normal?? (i know is not), any idea what this could be???, should i just go and buy a new lighter plug???

 

Not normal. A new lighter plug won't fix that. All I can think of is to check your fuses. Maybe something in there could cause that?!?!