Wiesinger, 39, who has recently been working with the club's youth academy, and Reutershahn, 52, an assistant under Hecking, will take the reins for the second half of the season.
The team are fifth from bottom in the table after drawing 1-1 at Werder Bremen on Dec. 16, their final match before the mid-season break.
Nuremberg said Wiesinger, who played 186 league games for the club between 1993-99, would have the final say on team matters.
"In Michael Wiesinger and Armin Reutershahn we have two coaches from our own ranks that enjoy a great amount of trust and acceptance," sporting director Martin Bader told Nuremberg's website (www.fcn.de).
"Michael has achieved great things with the youth setup and should bring a fresh impetus with him."
Wiesinger played for several clubs during his career including Bayern Munich and 1860 Munich.
He was a Champions League winner with Bayern in 2001 and helped them land the Bundesliga title twice and the German Cup once.
Wiesinger had a spell as coach of lower-league Ingolstadt from 2008-10.
"Nuremberg is my club," he said. "I was a player here and have put my heart and passion into my work here over the past year and a half.
"To get the chance to take on this challenge is very special for me."
Reutershahn is one of the most experienced assistant coaches in the Bundesliga, having previously worked at Bayer Uerdingen, Hamburg SV and Eintracht Frankfurt.
"Armin is an important constant for the team," said Bader. "We have come to appreciate his skills and qualities as a person and coach."
Wiesinger and Reutershahn will be officially presented at a news conference on Jan. 3.