To_char conversion issue

Hi All,
I have incoming source colum with datetime datatype. In the query mapping within the designer I made a chage to the format as
to_char(ORDER_PROC_2.SPECIMN_TAKEN_TIME,'MM-DD-YYYY HH24:MI:SS') and run the job but in the target table all the column values came out as NULL. Can someone please shine some light on this.

Source and target is oracle 11g
BODS(3.2).

Thanks.