I have a 1999 mercedes e320, it won't start! the tow light is on?

a mechanic told me since my tow light is on. my car won't crank. the spark plugs aren't getting any fire. and the fuel is not traveling up to the engine. Basically my whole car has shut down. Since it's on. Does anybody have a clue how to turn it off, disable it. or is there a part in particular i need to purchase. please give me some feedback