CLK430 Ignition won't turn

[BenzGal65]

Key won't turn in the ignition. Called service, they said that it was the battery and we're working on that but I still wanted to hear other opinions here because the car started with no problem earlier. Any ideas?

 

[BlackC55]

Ignition switch and they key are known problems to cause this.

 

[television]

Its normally the switch but it could be low voltage