President Carter installed a new Democratic Party chairman yesterday and promised "much closer" cooperation with his fellow Democrats than in the past.

Speaking to a special meeting of the Democratic National Committee, called to ratify his choice of Texan John C. White as the new party chairman, Carter acknowledged that last year "I don't think you [Democrats] had the kind of support you needed from the White House."

But he blamed that on the crush of work in his first year as President and promised that "this year there will be a much closer allegiance and alliance between the Democratic National Committee and the White House."

Carter's remarks confirmed reports from White House aides that he would step up his political activities in this election year, doing at least five party fund-raisers and making numerous appearances on behalf of Democratic candidates.

The White House announced yesterday that on the weekend of Feb. 17-18, Carter will visit Maine, New Hampshire and Rhode Island - all three of which have Democratic senators up for re-election.

Carter's aloofness from party affairs in 1977 led to serious patronage and policy complaints from state party officials. That was part of the problem that led to the resignation late last year of the previous chairman, former Maine Gov. Kenneth E. Curtis, an early Carter supporter.

At yesterday's ceremony, Carter praised Curtis for a "superb job," including the reduction of the Democrats' carryover debt to less than $2 million. Curtis, in turn, told the committee that as he goes back to his Maine law practice, "the state of the Democratic Party has never been better."

But White, who resigned as deputy secretary of agriculture to become the third party chairman in 13 months, immediately signaled he would clean house at the Democratic National Committee, whose staff has itself been a subject of frequent criticism.

The 53-year-old self-described "precinct politician," who won election 13 times as Texas agriculture commissioner, told the party's executive committee he wanted a "small, really professional staff, with no backbiting or petty warfare.

He won immediate power from the executive committee to reorganize the staff and indicated he would risk some controversy by naming Dan Horgan, a New Jersey political organizer, as his right-hand man in that effort.

Horgan, who ran the successful Carter campaign in Ohio in the fall of 1976, incurred the enmity of powerful Democratic leaders in his own state of New Jersey by breaking with Gov. Brendan Bryne (D) and opposing him for renomination in 1977.

New Jersey Democratic Chairman Richard J. Coffee, a Carter and Bryne ally, said he had told White that Horgan had "betrayed" Byrne and "was not beyond doing that at the national level."

But despite that threat and the opposition of some United Auto Workers leaders, stemming from disagreements over Horgan's management of the Carter campaign in Ohio. White announced he was naming Horgan as a full-time "consultant" on reorganization of the national committee.

White House aides, who had been critical of Curtis' staff, predicted that Horgan would become the party's executive director.

In his talk to the national committee, Carter said he had spent "hundreds of hours" in 1977 familiarizing himself with the problems of government, adding that he had put those responsibilities ahead of his political duties.

But now, Carter said, that learning process is largely complete and he wants to have a "full partnership" with the Democratic Party in carrying out his program.