Doug Patton resigned yesterday as Democrat Walter E. Fauntroy's campaign manager and was replaced by cable television executive Robert L. Johnson -- the latest shake-up in a mayoral campaign that has been plagued by administrative difficulties.

Patton, who could not be reached for comment, is resigning for "personal reasons" and is returning to his previous post at the Federal Election Commission, according to Johnson.

Johnson is president of Black Entertainment Television and a longtime political supporter and fund-raiser for D.C. Mayor Marion Barry. He switched to Fauntroy's camp after Barry's arrest on a drug possession charge in January.

He becomes Fauntroy's third campaign manager since Fauntroy announced he was giving up his nonvoting House seat to run for mayor. Fauntroy's campaign has been criticized by local political operatives for lacking sufficient direction and organization.

"It is not a sign of chaos," Johnson said of the change. "We are developing a good ward and precinct strategy . . . . I feel very confident that Walter Fauntroy is going to be elected."

Johnson, 44, has been involved in several political campaigns and served as Fauntroy's congressional press secretary from 1973 to 1976. More recently, he put together the consortium that bid successfully for the city's cable television franchise.

Johnson said his business responsibilities would not hamper his involvement in the Fauntroy campaign. "I'm going to be fully involved in everything -- to planning where he goes, to what he says, to who he meets with," Johnson said.

In a separate matter, Sterling Tucker resigned his position as the city's anti-drug czar during the weekend to run for Fauntroy's seat in Congress. Tucker, a former chairman of the D.C. Council, has scheduled a formal announcement for tomorrow.