Rep. James T. Broyhill announced yesterday that he will run for the Senate seat of ailing John P. East (R-N.C.), setting up a potentially bitter 1986 primary battle between the moderate and New Right wings of the North Carolina Republican Party.

Broyhill's chief opponent is David Funderburk, a former U.S. ambassador to Romania endorsed by East and the National Congressional Club, the powerful New Right political machine built by Sen. Jesse Helms (R-N.C.).

Broyhill, the dean of the North Carolina House delegation and a pillar of the party's moderate wing, made his announcement just four days after East said he would not seek reelection because of health problems. Hypothyroidism hospitalized him for weeks this spring.

Funderburk, 41, is a Campbell College government professor who has never run for office. A primary is expected to reopen a long-simmering rift between mainstream Republicans of the Piedmont who stress fiscal conservatism and the New Right Republicans, who place more emphasis on social issues.

"It's liable to get very, very bad. We've seen how the Congressional Club operates and could get very mean," said one leading North Carolina Republican.

Broyhill tried to deemphasize the split at a news conference attended by two North Carolina GOP colleagues, Reps. Howard Coble and J. Alex McMillan III. "I'm not running against the Congressional Club," said Broyhill, calling himself a conservative. "I'm offering my experience and leadership."

He said Helms, the leader of New Right forces in the Senate, and Gov. James G. Martin, a moderate, had promised to stay neutral in the race.

Palmer Sugg, a Funderburk spokesman contacted at the National Congressional Club offices in Raleigh, said he expected "a hard-fought primary." He added, "The moderate wing of the Republican Party has never had a great love for Sen. Helms or other real conservatives."

Regarding another 1986 Senate campaign, Geraldine A. Ferraro, last year's Democratic vice presidential candidate, said she would decide in November if she will try to unseat Sen. Alfonse M. D'Amato (R-N.Y.). She told a luncheon audience at the National Press Club yesterday that she had formed an exploratory committee and commissioned a poll, which she would consult to see if there was a "strategy to win."

"I would love to be in the Senate," the former House member said. ". . . . Washington is a super city to work in. There are lots of super people in both the House and Senate. I would love the opportunity to serve again. But that isn't enough for me to run. I'll have to see how all the pieces fall into place."

She said she "would not be surprised to see the Democrats recapture the Senate" majority in 1988, and she disputed "folklore" that the country is turning to the right.

President Reagan won reelection last year because of "strong personal popularity and because people were voting their pocketbooks, voting for the economic status quo," Ferraro said. She dismissed suggestions that Reagan's landslide victory was an affirmation of his conservative ideology.

"The polls showed that on the issues the American people agreed with Fritz Mondale and me," she said, referring to presidential candidate Walter F. Mondale. "That didn't translate as a vote for Fritz and me but it did translate on the next line down. The people returned a solid majority of Democrats to the House and elected two more new Democratic senators and gave the Democrats control of a big majority of the state houses."