Maybe you have a bad charger? Mine's a refurb, but through Amazon. You can get another wall wart through Amazon - maybe Walmart.
Does your charger have the interchangeable plugs? Mine does, and the plug might not be sitting in the charger right.
Know anyone with with a Voltmeter?
I hope you aren't trying to use a car charger - most don't work. I just bought an inverter for the car.