Philadelphia's city council passed a resolution yesterday mourning the death of police officer James Ramp - killed in a raid on the heaquarters of the radical sect MOVE - at the same meeting that it approved plans for voters to amend the Philadelphia city charter to permit Mayor Frank Rizzo to run for an unprecendented third term.

Rizzo, who is completing the present maximum of two terms, is widely believed ready to run again if the charter is amended.

The vote mourning officer Ramp was unanimous. The vote on the charter resolution split 12 to 4; only Democrats, only one of the five black councilmen voted in favor of the measure.

The tying together of the two votes was a coincidence but a peculiarly ironic one. Rizzo, a former policeman whose tough law-an-order image helped elect him mayor, had emerged as a major antagonist of the MOVE group, calling them "animals," declaring that police would "respond with more fire power than anyone has ever seen" if MOVE members ever fired at them and declaring that he would pull the switch himself if MOVE members were sent to the electric chair.

For months as the confrontation built up around the west Philadelphia of MOVE (the meaning of the apparent acronym has never been explained) the street of center city had been full of long tables lined with petitions and with people haranguing passersby over loud speakers. Half the petitions were asking the Council to allow the charter change to be put up to a November vote, half were asking Council to reject it. But the charter was rarely mentioned. Instead, under huge signs that said Stop Rizzo or Keep Frank Rizzo in City Hall, the speakers talked about "the greatest" - or "the worst" - mayor in the country, whose term expires in 1979.

Meanwhile, MOVE members from their makeshift fortress had proclaimed that they were going to finish Rizzo once and for all by forcing him to back down in their confrontation.

Many observers agreed with the Philadelphia Daily News columnist who wrote yesterday that "at least some Philadelphians viewed the MOVE confrontations as a racial issue. And the conventional wisdom among local politicians is that racial issue helps Rizzo because it strengthens his support among blue-collar whites."

Black elected officials met yesterday to criticize the brutal beating of one MOVE member after he had surrendered and in a letter to U.S. Attorney General Bell, demanded a federal investigation of the Tuesday raid. Police officers have demanded and won, a special meeting of the Fraternal Order of Police - the official police organization in this city - to hear charges that the raid was so poorly planned and carried out that Ramp's death may have been the result of panic or confusion among high police officials.

Many eyewitnesses to the raid, including reporters and cameramen, have said that the first shots came from a building across the street from MOVE headquarters, behind police lines. But Police says ballistics tests that they refuse to release prove the gun that killed Ramp was fired by a MOVE member.

A group of black youths marched last night to the site of MOVE headquarters to denounce police and Mayor Rizzo. The headquarters, a garbage-filled, ramshackle Victorian mansion that had housed a dozen adults, 11 children, more than 40 dogs and unnumbered rats, was leveled by police order shortly after the raid. A lawyer for the MOVE organization had obtained an injunction against the destruction of the building, but not in time to save it.

Many black leaders have criticized the quick destruction of the building, saying it may have buried evidence that could have settled the question of where the first shots were fired from and who killed Ramp and wounded the policemen. Rizzo has responded that there is no question at all that MOVE - and MOVE alone - is responsbile. As a result of yesterday's council vote, enough voters may now get a chance to agree with him to make him mayor of this city for a long time to come.