Moldenhauer's career began in 1954 at BSG Motor Mitte Magdeburg, the football department of which formed a section of SC Aufbau and later became 1.

Aside from his footballing career, Moldenhauer passed the abitur and studied mechanical engineering at Magdeburg's Technische Hochschule.

Only after Blochwitz had left for FC Carl Zeiss Jena when Magdeburg were relegated in 1966 did Moldenhauer become the regular keeper.

Moldenhauer had received an offer from Magdeburg's SKET, a producer of heavy machinery, to work in a senior position there.

On 31 March 1990 Moldenhauer was elected President of the DFV and initiated the merger with the DFB that was completed on 20 November 1990.

In 1991 Moldenhauer founded SV Oldies Magdeburg, a sports club he himself stays fit in and occasionally plays football matches.