William C. Cartwright, senior vice president and manager of the BankCard and Electronic Services Division of First Security Service Co., has been elected a member of the Plus System Inc. board of directors.

Formed in 1982, the Plus System is a not-for-profit organization of more than 3,000 financial institutions which operate the nation's premier share automated teller machine network. More than 170 million credit and deposit access cards have been issued by the system-member banks in 160 countries around the world.Cartwright joined the company as a computer programmer in 1969, became programming manager in 1975 and in 1976 was elected as assistant vice president and advanced to vice president and BankCard Center manager in 1977. He was elected a senior vice president last January.