Elcar was born in Ferndale, Michigan, the son of Hedwig (née Anderberg) and James Aage Elcar, a carpenter and butcher. Elcar was an alumnus of the University of Michigan where he was a member of the Alpha Tau Omega fraternity. Elcar served a tour a duty in the United States Navy. Elcar was also a student of legendary acting coach Sanford Meisner. He brought this education to bear when in 1986, with fellow character actor William Lucking, he formed the Santa Paula Theater Center. Elcar sat as artistic director for six years. Elcar also had supporting roles in films such as Fail Safe (1964), A Lovely Way to Die (1968), The Boston Strangler (1968), The Maltese Bippy (1969), The Learning Tree (1969), Zig Zag (1970), Soldier Blue (1970), Adam at 6 A.M. (1970), A Gunfight (1971), The Great Northfield Minnesota Raid (1972), The Sting (1973), W.C. Fields and Me (1976), Baby Blue Marine (1976), St. Ives (1976), The Champ (1979), Good Luck, Miss Wyckoff (1979), The Last Flight of Noah’s Ark (1980), Condorman (1981), Buddy Buddy (1981), Jungle Warriors (1984), All of Me (1984), and 2010 (1984). In 1962, he was first cast on the long running CBS daytime drama, The Guiding Light as Andrew Murray, the District Attorney of Los Angeles County. Later in 1962 and 1963, due to his stint on The Guiding Light, he was cast in three episodes of the NBC sitcom, Car 54, Where Are You?, and two segments of the ABC crime drama, Naked City, both set in New York City. In 1966 and 1967, Elcar played Sheriff George Patterson on the vampire soap opera Dark Shadows.

He played Inspector Shiller, the supervisor, in the crime drama, Baretta, starring Robert Blake. He had a recurring role in the 1970s television military drama, Baa Baa Black Sheep, starring Robert Conrad, and guest starred on CBS’s Mission: Impossible and Storefront Lawyers in 1970 and in 1971 he was a guest star on “Ironside (1967 TV series)”. He was also on The Waltons and Kung Fu in 1973, and appeared in TV disaster movies such as Heatwave! (1974) and Crisis in Mid-Air (1979). In 1979 he played judges in Centennial and B. J. and the Bear. In 1980, he was cast in the role of “Chief” in the Get Smart feature film entitled The Nude Bomb (a.k.a. The Return of Maxwell Smart) that was based on the 1960s hit TV series (the role previously played by Edward Platt, who died in 1974). He also co-starred in two episodes of The A-Team in 1984 and 1985. In 1987, he was cast on Andy Griffith’s legal drama, Matlock. Elcar and his stunt/photography double, Don S. Davis, were often mistaken for each other. Elcar appeared in the hit series Knight Rider in the 1983 episode “Merchants of Death”; as a corrupt sheriff in The Incredible Hulk episode “Escape from Los Santos” (1978), in which Banner is headed to Phoenix; and as KAOS Agent Kruger in the 2-part 1969 episode of Get Smart entitled “And Baby Makes Four”. In 1991, Elcar began to develop glaucoma. This condition was written into the show, MacGyver, beginning with the sixth season episode seventeen “Blind Faith” and continuing through the remainder of that season and the entire seventh season, with Elcar’s character developing the disease. The sixth season finale, Hind-Sight, was a clip show using Pete Thornton’s upcoming eye surgery as a framing device. After MacGyver, Elcar made a guest appearance in “Virus”, a 1993 episode of Law & Order, in which he played a man who blamed his diabetes-caused blindness on his former physician, and whose son murdered other patients as revenge.

Elcar also played a blind character on episodes of The Magic School Bus and ER. Once blind, Elcar took on the challenge of playing Vladimir in Waiting for Godot complete with white cane. This was his theatrical swan song, and he retired in 2002 after his ER performance. On June 6, 2005, Elcar died at the Community Memorial Hospital in Ventura, California from pneumonia. He was 77 years old. He was survived by his son, Dane Elcar; his three daughters (Nora, Chandra and Marin); a stepdaughter (former soap opera actress and current writer Emily Prager); a sister; a half-sister; and his long-time partner, Thelma Garcia.