[1][2][3][4] Fechner was born on 27 August 1913 in Berlin, the capital of the German Empire at the time.

He joined the Sozialistische Arbeiterjugend (SAJ) or Socialist Workers' Youth (in English) in 1927 at the age of 13.

Fechner served for Nazi Germany during World War II.

After the end of the war in 1945, he joined the Social Democratic Party of Germany (SPD) and was a member until 1946 when the SPD and the Communist Party of Germany (KPD) merged, then remained a member of the newly formed Socialist Unity Party of Germany.

Additionally, Fechner was the President of the Federation of German Sailors for nearly thirty years, serving from 1961 to 1990.