Howard Hesseman, who played the radio disc jockey Dr. Johnny Fever on the sitcom “WKRP in Cincinnati” and the actor-turned-history teacher Charlie Moore on “Head of the Class,” has died. He was 81. Hesseman died Saturday in Los Angeles due to complications from colon surgery, his manager Robbie Kass said Sunday. Hesseman, who had himself been a radio DJ in the 1960s, earned two Emmy nominations for playing Johnny Fever on CBS’ “WKRP in Cincinnati,” which ran for four seasons from 1978–1982. Hesseman’s credits also included “The Andy Griffith Show,” “One Day at a Time,” “The Rockford Files,” “Laverne and Shirley,” and “The Bob Newhart Show.” More recently, he made appearances on “That 70’s Show,” “Fresh Off the Boat,” “House” and “Boston Legal.” Films included “Police Academy 2: Their First Assignment,” “About Schmidt,” “This Is Spinal Tap,” and “The Rocker.” Hesseman is survived by actor and acting teacher Caroline Ducrocq, …