Two Harvard University law students are taking on the Defense Department and the Army by challenging the constitutionality of the government's military chaplain programs.

The students, Joel Katcoff, 24 and Allen Wieder, 23, contend the $65-million-a-year Army chapliancy program is prohibited by the First Amendment's ban on government support of religion.

A decision in their favor could affect not only the 1,400 active duty Army chaplains, but another 1,700 Navy, Air Force and Marine active duty chaplains and nearly 1,700 reserve, Coast Guard and National Guard government chaplains, such as those who minister to the House of Representatives and Senate.

Wieder and Katcoff said they decided to challenge the chaplaincy program after looking for "blatant violations" of separation of church and state while studying constitutional law.

The chaplaincy program, which has operated since the Revolutionary War, was challenged once before, in 1928, but the Supreme Court dismissed that case because the plaintiff could not prove he had been harmed. But in 1968, the high court ruled that in cases involving an issue of separation of church and state, plaintiffs can file suit for relief as taxpayers.

The Air Force chief of chaplains, Maj. Gen. Richard Carr, said he believes the military chapliancy poses no threat to the First Amendment. "The military chaplaincy has been sanctioned not only by the Congress but there hasn't been a president who has not validated [it]."

Chaplain George Evans, chief of Marine chaplains, said the program is on "solvent constitutional grounds" because there have been military chaplains since colonial times and they [early military chaplains] were "supported by the very people who supported the Constitution."

The Army and Navy chief chaplains refused to comment on the issue.

The students also charge that the military chaplaincy inhibits the free exercise of religion among military personnel. "We make argument with the effects the Army has on the chaplain. It determines when he gets a merit raise, when he's promoted, . . ." said Katcoff.

They said that as a result, the chaplains are forced to mold their views to the Army's.

The students also charge that the program discriminates against nonmainline religions institutions.

"We're not seeking to eliminate the chaplains from the Army," said Wieder.

"We're just seeking to replace the current Army-run program with a privately funded program."

"We're saying it's all right for religion to flourish in the Army" but it doesn't have to be separate from the community," he said. "Individual servicemen should inquire within the community or their own denominations to seek clergy," said Wieder, "just like people in Kellog, Idaho."

The students have filed their suit in the U.S. District Court for Eastern New York. A judge is now weighing whether to hear the case brought against the U.S. Army, the Defense Department and Army Secretary Clifford L. Alexander Jr.

A team of Army defense attorneys hopes the case will be dismissed on one of several grounds: That the students are not taxpayers and therefore not injured, that the chapliancy program does not violate the First Admentment and that the question is political and "not subject to judicial reveiw."