Susan Truitt, 40 years old and mother of six, was late. It was her third political gathering of the evening - after a full day of campaign meetings and organizing sessions that had begun at 6 a.m.

She was clearly tired.

But Truitt, an independent candidate for the vancant at-large City Council seat in next Tuesday's special District of Colubmia election, said she could not pass up the opportunity to seek more votes.

She quick-stepped down the long, nearly vacant corridor leading to the Woodrow Wilson High School autitorium, checking her appearance - without missing a step - as her image was reflected in windows along the corridor.

"I'm in luck. They've still here," Truitt said, as she entered the audiotrium where D.C. Rep. Walter Fauntroy was holding a ward three town meeting. "You see, politics is mostly luck," she said.

In her race against nine other candidates for one vacant City Council seat, Truitt said she knows if takes more than luck to win an election.

She is in what she considers an uphill race against two candidates in particular - Barbara A. Sizemore and Hilda H. Mason - women she considers poltical Goliaths. Truitt says she's a David without any stones - at least "not yet."

"I know I've got a big fight ahead of me," she said the other day. "But I've never backed down from a fight."

The most recent test of Truitt's resolve came last year, when she served as a special assistant to Joseph P. Yeldell, the former director of the D.C. Department of Human Resources. Truitt was hired at more than $30,000 a year to help improve the image of Yeldell and DHR, which was tarnishing under a growing barrage of newspaper articles and government reports alleging widespread mismanagement of the city's largest department.

After 10 months on the job, Truitt was unable to repair the strained relations. Some reporters criticized her as a personal obstacle to better communication with the DHR bureaucracy. Disgruntled with the way she was doing her job, the City Council cut Truitt's budget request for 17 additional persons to four.

By last November, Yeldell's departure as DHR director was imminent. An unprecedented string of newspaper stories accused him of serious hiring and leasing abuses and conflict of interest. Truitt, feeling hemmed in by the controversy, quit.

Some of Yeldell's strongest allies in DHR criticized the veteran television reporter for Yeldell's shattered image. They also ridiculed her for "jumping ship early," as one DHR worker said, leaving as soon as Yeldell's job seemed seriously in question and at a time when morale in the agency was at an all-time low due in large part to increasing media criticism.

Truitt saw it differently.

"I resigned when I was convinced we (her public information unit) were immobilized by the controversy and the year was not as productive as I thought it would be," she said.

"I don't regreat having worked for Joe," Truitt said. "I have no regrets about being a spokesman for him. When I took the job, it was with the understanding that I would develop an information program so that the community would have easy access to information about DHR.

"The job was not public relations, not image building, but getting information to the public," she insists.

Sometimes defensive when asked about her role at DHR and how it now affects her chances in this election, Truitt attempts to cast it all aside with a shrug of her shoulders.

"It's not believable that I am Joe Yeldell," Truitt says. "Joe is like a double-edged sword. In some parts of town, he's a hero who got a raw deal. In others, he's a villain."

I'm sure there are some people who are very critical of Joe, but after I talk to them for awhile, I'm usually able to get past any negative feelings they may have about him and talk about my candidacy."

Truitt said she purposely stayed away from what she called "personality politics," the "lining up of support from potential mayoral candidates" in the 1878 city-wide election.

"I have neither asked for, nor gotten support from, members of the Council, the mayor or Yeldell," she said. "They've given me no help financially or through their own campaign organizations.

While that may be the case, most Truitt's brief political visibility has all come in connection with the mayor's administration. In 1975, she worked as a media adviser to Washington andthen later as the chief press aide for Yeldell.

In addition, several persons who traditionally have been involved with the mayor's own political movement now are actively involved with Truitt's. Her campaign treasurer, for exampl, is Elizabeth Eastman, the wife of mayoral press secretary and confidant of Sam Eastmen.

In an off-year election campaign plagued by few financial contributors and a limited reservoir of active campaign workers, Truitt, like most other candidates, has become a virtual one-woman political show.

She is emphasizing the need to spur greater economic development in the city as a principal part of her program. More business means more commercials taxes, she reasons, and that will lessen the property tax burden on D.C. homeowners.

For those who rent, Truitt favors eliminating rent control - but not right away, as incorrectly implied by a caption beneath a photograph of her in yesterday's Washington Post. "We need it over the short haul," she says. "Over the long haul, if we give business incentives to build moderate income housing then we can phase rent control out."