He was named an assistant coach with the San Francisco 49ers on February 14, 1968, spending the next seven seasons with the team until being hired as head coach of the Kansas City Chiefs on January 23, 1975. After compiling an 11-24 mark in less than three seasons, Wiggin was fired following a 44-7 loss against his old team, the Browns, on October 30, 1977.
After Dick Nolan was named as head coach of the New Orleans Saints in 1978, he once again hired Wiggin as the team's defensive coordinator. Spending two years in the position, Wiggin then was hired as head coach at his alma mater, Stanford, on February 1, 1980.
Despite the presence of quarterback John Elway on the team during his first three years, Wiggin was unable to lead Stanford to a bowl game during his tenure and was dismissed following the 1983 season with a 16-28 record over four years. Wiggin's efforts to reach a bowl game had come agonizingly close in 1982, when his team fell victim to what simply became known as The Play on November 20. In an incredible finish against the University of California, the school's arch-rival, Cal lateraled five times in the closing seconds to score the winning touchdown.