He also played for Parcells as a running back on the New York Giants' two Super Bowl winners.
He replaces Bruce Coslet, who was with the Cowboys for just one season.
Zimmer has been on Dallas' staff for nine seasons, the last three as defensive coordinator. The Cowboys had the NFL's 18th-ranked defense in 2002, a year after ranking fourth.
Carthon spent the past two seasons with Detroit, last season as offensive coordinator after a year as running backs coach. Before that, Carthon was on Parcells' staff as assistant head coach and running backs coach for the Jets -- 1997-00, the first three under Parcells -- and running backs coach with New England in 1994-96.
He played eight NFL seasons, ending his career in 1992 with Indianapolis after the first seven years with the Giants for Parcells.
Under Coslet, the Cowboys had the NFL's lowest-scoring offense, averaging fewer than 14 points a game. The team was unable to make the transition to his West Coast-style offense.
Parcells was hired Thursday by the Cowboys, who are coming off three consecutive 5-11 seasons and haven't won a playoff game since 1996.
He has coached 15 NFL seasons, having taken the Giants, Patriots and Jets from losing records to the playoffs in two years. He had been out of coaching since ending a three-year stint with the Jets after the 1999 season.
Parcells Moving Swiftly
CowboysHQ Top Stories
Cowboys 25 Reunion: Jimmy + Jerry (+ Barry)!The day started with Barry Switzer tumbling down the stairs. The night ended with Jerry Jones climbing up the stairs. And on the platform in between? Jimmy Johnson, the…
CowboysHQYesterday at 9:19 AM
Cowboys 1st +10: Combine Crunch To NFL DraftEach weekend I provide 10 quick hits on the Dallas Cowboys. The NFL Scouting Combine is next weekend and I share my memories of my time in Indianapolis in this edition of First and…
CowboysHQSaturday at 9:44 AM
StarCast: Dishing On Cowboys Week (+ Summer)StarCAST: Dishing On The Cowboys Week - And The Cowboys Summer
CowboysHQFriday at 12:36 AM
Cowboys Elliott 'Detained By Police'? NopeDallas Cowboys Star Ezekiel Elliott 'Detained By Police'? Nope - But The Scrutiny Is Never-Ending
CowboysHQWednesday at 6:48 AM
Cowboys STARCast: Cavanaugh On The NFL DraftCowboys STARCast: Jeff Cavanaugh Joins The CHQ Podcast To Talk NFL Draft.
CowboysHQTuesday at 4:15 PM