Is There a Ratings Doctor in the House? : Television: CBS gives ‘Island Son’ a new time slot, moving it from Tuesday to Thursday.

“There are strange, large forces at work in this business of getting a show on the air,” Richard Chamberlain mused.

The very civilized Chamberlain--lunching on the Hawaiian fish mahi mahi in the noonday sun, immaculate in crisp casual clothes in coordinated shades of mint green--would not be so impolite as to blame anyone for the fact that his new CBS medical series, “Island Son,” is foundering in the Nielsen ratings. It ranks 61st among 85 network prime-time series this season.

The closest Chamberlain comes to pointing a finger is to note that the series, which marks the former Dr. Kildare’s return to TV as a physician, had somehow veered off course as a result of the aforementioned strange, large forces--and that the show’s producers are now struggling to get it back.

“I don’t think you can ever blame anything on anyone else,” Chamberlain said evenly. “Well, maybe once in a while--but it doesn’t do any good. I mean, I could say a few things that weren’t handled just right, but then, there are a few things that I didn’t handle just right either.”

Although declining to offer specifics, Chamberlain said the first episodes of the show were rush jobs due to delays and illnesses among the cast and crew.

Tonight, in an effort to improve its fortunes, “Island Son” gets a new 9 p.m. time slot, moving from Tuesdays at 10. Although some might call the new position a death slot opposite NBC’s popular comedies “Cheers” and “Dear John,” Chamberlain said he prefers it.

“We have a stronger lead-in (“48 Hours”) and lead-out (“Knots Landing”),” said the veteran actor, who also serves as executive producer of the series.

That’s not the only change afoot. As quickly as new scripts can be written, Chamberlain said, the show will widen its focus beyond the hospital walls to better utilize the show’s lush Hawaiian setting.

Chamberlain’s Dr. Daniel Kulani will also widen the scope of the show with more house calls, and his ex-wife will show up to stir up a little trouble in his personal life.

He has not yet gotten the green light from the network, but Chamberlain hopes the show not only will move outside the hospital, but also will focus more on traditional island medical techniques than on modern medicine.

“I think people will find it much more interesting when we are dealing with genuine Hawaiian issues, and much more with the personal problems and dramas of the regulars,” he said. “I think what is no longer wildly interesting to people is pure medical stuff: ‘It’s your gall bladder, ma’am.’ ”

He also believes that, despite the failures of Mary Tyler Moore and Dick Van Dyke in their return to series television last season, they want to see familiar faces--provided they have the right vehicle.

“It’s the show, the energy and the person,” he said. “There’s not a rule in the book that can’t be broken with the right energy, the right concept.”

Chamberlain said that, as executive producer of his show, he must avoid the trap of fashioning his own character as a white-coated hero in the mold of the Dr. Kildare character he played from 1961-66, particularly in the wake of more realistic medical shows such as “St. Elsewhere.”

“I wouldn’t be surprised if a lot of people in the audience long for that simplicity, but I don’t think they quite believe it anymore,” he said. “Ideally, I’d like to see him (Dr. Kulani) as a man on the brink of a lot of discovery. . . . I see him as somewhat driven, which makes trouble with his relationships. I want to see him more and more in a position where he has to learn something, rather than teaching some kind of moral lesson.”