2003 e320 starter will not turn over

Check your battery conecections make sure they are clean and have a good connection. And also make sure your battery is good

The battery should be newer than five years old, as indicated on the knock- off labels on the top of each battery indicating the date of the first charge...they stop accepting a charge approximately ten percent per year...after that the alternator works double-time just to keep the charging system afloat~ as my associate Ronc258 has stated wirebrush the main ground (end of the black 1/0 cable) where it bolts to the system ground...and wirebrush the ground point too, to assure 300 cold cranking amps at the very least~