U.S. Information Agency Director Charles Z. Wick, confronted by an ideological dispute that has hampered selection of a new boss for the Voice of America, has picked Richard W. Carlson, a former California journalist and unsuccessful candidate for mayor of San Diego in 1984, as acting VOA director.

The VOA post has been vacant since last fall, when E. Eugene Pell left to become president of the Munich-based Radio Free Europe and Radio Liberty. Wick and his deputy director, Marvin Stone, tentatively tapped William Sheehan, former president of ABC News, as Pell's successor. But the move has apparently been stymied by conservatives who have lobbied at the White House for a replacement of more conservative stripe.

Sheehan also failed to pass muster with a group of movement conservatives who questioned him at a recent luncheon arranged by New York lawyer Roy Cohn. Among his sins were his avowed identity as a political "centrist," his refusal on principle to say for whom he had voted in past presidential elections, and his insistence that the VOA's worldwide news broadcasts should conform closely to congressional strictures about impartiality.

Candidates with strong conservative backing include William Gavin, the chief foreign policy aide to House Minority Leader Robert H. Michel (R-Ill.); Ken Thompson, currently the chief editorial writer for the VOA; Charles Lichenstein, who was a deputy to former U.N. ambassador Jeane J. Kirkpatrick (and perhaps best known for his public suggestion that the United States would be happy to see the U.N. depart these shores), and Burton Pines, a vice president of the conservative Heritage Foundation.

USIA sources suggest that Wick and Stone, who still hope to get a VOA director with strong credentials in broadcasting, turned to Carlson as a stopgap. The sources said the hope is that Carlson has the political and the professional credentials to make him acceptable both to conservatives and to the VOA's career employes while the search continues for a permanent occupant of the director's office.

Political Shiner . . . For any Democrat with presidential ambitions, political terminology is a touchy issue these days. Take the case of Don Foley, press secretary to Rep. Richard A. Gephardt (D-Mo.). Foley was recently seen sporting a large bandage over his left eye, which is being treated for an infection. But that's not exactly what he's telling folks. "The one-liner is," quips Foley, "that somebody tried calling Gephardt a liberal."

Thoughts for Food . . . Among the highlights of Secretary of State George P. Shultz's black-tie reception for the Washington diplomatic corps last Friday night was a lavish buffet replete with tiny lamb chops, rosy-centered roast tenderloins, crisp duck wrapped in pancakes and myriad cakes swathed in whipped cream. But while the guests were piling their plates high, their host stood off to the side, munching crackers and stealing what appeared to be an occasional forlorn look at the food.

The reason became clear when Shultz spoke to the assembled guests. In a passage alluding to the effects of the Gramm-Rudman-Hollings budget cuts, Shultz said, "It won't hurt any of us to tuck in our belts a bit." He added proudly, "I know because I'm on a diet, and I've taken off 20 pounds."

Some senior State Department officials, who discreetly asked not to be identified, noted that Shultz's address, which seemed to them an interminable review of U.S. foreign policy, could be called "the Gramm-Rudman-Hollings speech." As one said, "It kept everyone away from the buffet tables for more than half an hour, and that must have saved us at least $5,000 on the food bill."