Opjordsmoen started his career in Raufoss IL, amassing 300 games across all competitions in ten seasons. Ahead of the 1983 season he went on to Hamkam.[1] He made a comeback in Raufoss in the summer of 1984.[2] He retired ahead of the 1986 season and became head coach.[3]
Opjordsmoen managed Raufoss until 1987, then again from the summer of 1988. Both his successors, Torbjørn Brobakken in early 1988 and Torfinn Overn in early 1990, were sacked after half a season.[4][5] Opjordsmoen went on to Nybergsund IL from 1991 to 1996 and Raufoss again from 1997 to 1998, leading the team into the 1998 1. divisjon.[6] In the autumn of 1998 he was interviewed as new manager of FK Haugesund,[7] but was instead hired in FK Bodø/Glimt.[6] He resigned in May 2001.[8][9][10]
In July 2001 he returned to Raufoss the day after Börje Andersson was sacked.[11] He quit his manager job after the 2007 season, when Raufoss was demoted from the 2007 1. divisjon for financial reasons.[12]