The administration's plan to resume military aid to Chile is being reassessed because of concern that the poor human rights record of the military regime there will expose President Reagan to congressional charges of bad faith and harm his policy toward Central America.

A lively internal dispute is under way within the administration about whether Reagan can legitimately certify that Chile has met the human rights test decreed by Congress before aid can be restored.

Opponents of restoration argue that if Reagan makes such a certification in the face of strong evidence to the contrary, he will give congressional liberals new ammunition with which to charge that plans for increasing aid to the civilian-military government in El Salvador are part of a larger pattern of propping up repressive Latin American military dictatorships.

In an effort to resolve the problem, Thomas O. Enders, assistant secretary of state for inter-American affairs, left yesterday for talks in Chile that will include an attempt to win new concessions permitting Reagan to make the certification.

However, some administration officials are understood to believe that Enders' trip is unlikely to produce the necessary results and that Secretary of State Alexander M. Haig Jr. might be forced to recommend temporarily shelving the renewed aid plan.

At issue is a provision adopted by Congress last December that gives Reagan qualified power to resume arms sales and other military aid to the regime of President Augusto Pinochet. The aid was stopped in 1977.

To do so, however, the president must certify to Congress that Chile has made "significant progress in complying with internationally recognized standards of human rights."

He also must certify that Chile is cooperating to "bring to justice" those Chilean officers indicted by a federal grand jury for complicity in the 1976 bombing murders here of former Chilean ambassador Orlando Letelier and an American associate, Ronni K. Moffitt.

In one of its first moves after taking office, the administration made clear it wanted to improve relations with Pinochet, whom it regards as a potentially important ally in its campaign against communist influence in Latin America.

In a gesture whose symbolic importance far outweighs its cash size, the administration tentatively has included $50,000 in military training funds for Chile in its fiscal 1983 security assistance request to Congress.

Originally, the administration planned to send the certification on Chile and Argentina, which Congress also has subjected to a similar human rights test, about the same time last month that it certified El Salvador's eligibility for U.S. military aid.

However, action on Chile and Argentina, which have been paired in State Department planning, was pulled back abruptly because of questions raised by some administration policy makers about Chile.

According to sources familiar with the internal debate, the most serious problem involves whether Reagan can certify that Chile is cooperating with efforts to extradite those indicted in the Letelier case.

Lawrence Barcella, assistant U.S. attorney in charge of the case, recently told The Washington Post:

"With respect to progress on the Letelier investigation, they Chilean officials haven't done spit since the day this thing happened. In fact, they have been dilatory and obstructionist."

The Justice Department is preparing an informal advisory opinion for the State Department and, while no decisions have been made, Justice sources said they believe officials there will be forced to conclude that Chile has not met the test for certification on the Letelier requirement.

In addition, the State Department's bureau of human rights has questioned whether there has been improvement in the Chilean human rights situation.

The bureau is understood to be particularly disturbed by a recent Chilean human rights commission report, which was released in this country by the Freedom House organization and charges that rights abuses in Chile have increased.

Congressional liberals led by Sen. Edward M. Kennedy (D-Mass.) have threatened that, if certification goes through, they will launch an all-out attack on the administration's Latin America policies.

As a result, many officials fear a congressional battle that could increase opposition to the already controversial policy of increasing aid to El Salvador and seeking strengthened military relationships with Honduras and Guatemala.

On the other side, Enders's bureau of inter-American affairs, backed by ideological hard-liners in the administration and Congress, are understood to advocate going ahead with the Chile aid plan.

According to the sources, the matter has not been referred for a final decision but a clearer picture of the outcome is likely to emerge from discussions this weekend involving Enders, Ambassador James D. Theberge, who was sworn in yesterday, and Chilean authorities.