The changing of the guard has just taken place in Harrison Ford's hotel suite. One reporter departs, and another enters. Ford excuses himself, disappears into the bedroom, then reappears momentarily.

Several days of interviews revolving around his new film, "The Mosquito Coast," which opens Wednesday, have worn on this naturally reticent actor. The film's director, Peter Weir, has canceled his own remaining interviews and returned home to Australia, claiming total exhaustion.

But Ford perseveres. He puts on a fresh face and, speaking in a soft voice, answers questions matter-of-factly. He admits not liking interviews. That actors have a public image bothers him. "Image is something I try not to think about very much. The movie-business side of me is aware of its importance. But as an actor, I don't care."

Ford says he gives interviews because it's part of an actor's job.

"A film represents the hopes of a lot of people. You (as a star) are the last link between them and the buying public. It's your responsibility to do (interviews). But it speaks for itself."

Something of this aloof and dogged independence seeps into all his roles. From the hot-rodder Bob Falfa in "American Graffiti," to the mercenary pilot Han Solo in the "Star Wars" sagas, or the grave-robbing archaeologist in the two Indiana Jones adventures, Ford invariably plays a rebel. He's a man who wants to get on with the job at hand - and he has his own ideas about how to proceed. Just don't bother him.

In "The Mosquito Coast" this fierce individualism is taken to an extreme. He plays Allie Fox, an inventor who is so disgusted with modern American society that he packs up his family and moves them to a Central American jungle where he can create a new society. For a while the family treats all this as an adventure. But dad's obsession with independence eventually threatens to destroy the whole family.

While in no way like Allie Fox, Ford has chosen the independent route in his acting career. When he became exasperated with the TV roles coming his way as a contract player for Columbia Pictures and later Universal Studios, Ford took up carpentry for a number of years.

"Through carpentry I fed my family and began to pick and choose from among the roles offered. I could afford to hold out until something better came along. But I never gave up my ambition to be an actor. I was frustrated but never felt defeated by my frustration."

During a period of six or seven years he appeared in only a few films. But what films! He did George Lucas' "American Graffiti," Francis Coppola's "The Conversation" (as a threatening business executive), the TV film "The Court Martial of Lt. Calley" (as "the witness who cries") and the TV movie of James Michener's "Dynasty" (as Sarah Miles' eldest son).

"Each one was a better part than I had before," he remarks. Then Lucas recruited Ford again, this time for "Star Wars" (1977), and that put an end to carpentry.

It did not bring real stardom, however. He kicked around in several leading roles mostly as soldiers or ex-soldiers - in "Heroes," "Force 10 From Navarone," "Hanover Street" and a cameo appearance for Coppola in "Apocalypse Now," without being able to establish a leading man identity with audiences.

"Raiders of the Lost Ark" changed all that. The public responded to his daring adventurer. Indiana Jones was cool under fire and had sex appeal galore. Harrison Ford had marquee value.

Despite stardom, the 44 year old actor still approaches acting as he did carpentry. "As a friend once said, the collar around my neck is blue. I know what it is to work and work hard. Acting is a job, a responsibility, a complex task - all those things. I approach all work from a workman's point of view. I expect to get my hands dirty, get into a sweat and work overtime."

Ford had no trouble getting into a sweat while filming "The Mosquito Coast" in the Central American country of Belize. "Belize is a pretty basic place - a poor country without developnent, but the right place to shoot this film. I'm sure glad we didn't try to recreate that environment on a back lot in South Carolina.

"The shoot was long, hot and humid, But I found it more exhausting mentally than physically because of the complexity of the role and the endless process of sorting out and reappraising where we were at. You had to be on your toes all the time."

Ford admits to having an intense involvement in the filmmaking process. But in this case it was increased. "All the sets that were built (in the jungle) were a representation of Allie Fox, a sign of his personality. So I was quite keen to know how all that was going. I had a lot more input than normally."

"The Mosquito Coast" represents a second collaboration between Ford and Australian director Peter Weir. Ford's performance last year as John Book, the Pennsylvanian police detective who seeks refuge in the Amish community in Weir's "Witness," resulted in a best-actor Oscar nomination for Ford.

While Ford was delighted at the opportunity ot work with Weir again, he stresses that the role of Allie Fox was his primary consideration. "The opportunity to play a really interesting and remarkable character doesn't come up too often in film literature. Many roles aren't meant to be complex. This one is all about complexity."

What Ford admires most about Weir's films is the craftsmanship. "He's extremely hard on himself, but he always ends up with high quality. I'm much the same way in terms of being hard on myself. The combination of our two personalities stimulates each other. We come from different backgrounds, but our ideas are surprisingly similar."

Ford was born on the North Side of Chicago, the son of an Irish Catholic father and a Russian Jewish mother. He was reared in Park Ridge and Morton Grove, and studied philosophy and English at Ripon College, a small liberal arts school in central Wisconsin.

His grandfather had been a vaudevillian, and his father dabbled in radio acting and writing before becoming an advertising executive. But Ford said he never gave a career in acting any thought until he was "flunking out of college and trying to figure out some kind of job."

Ford saw acting as a job that incorporated many enjoyable activities - travel, meeting interesting people, playing a whole range of individuals and not having to do the same thing day after day. "I can't belive how ignorant I was of the difficulty," he now says. "I mean, I was not starry-eyed, but I just didn't realize how hard it could be."

Stardom was something to which he never aspired. "My only ambition was simply to work as an actor. But it didn't come naturally at all. I was shy. I had a fear of getting up in front of people to overcome. It certainly helped when you could put on a mustache or dye your hair black and become somebody else."

After working in summer stock, he moved to Laguna Beach in 1964 and appeared in the Playhouse production of "John Brown's Body." This led to his signing a $150 a week contract at Columbia. He made his film debut as a bellhop in "Dead Heat on a Merry-Go Round."

"The principal problem (with the contract system) is they were trying to mold people into movie stars. They were picking people with individuality and then kicking th