NEW FALL TV SEASON : THERE’LL BE SOME CHANGES MADE

It’s not unusual for a character in a TV series to be killed off, but the new season will bring not only one passing and the resolution of a possible death but also two resurrections.

These are some of the changes that producers have made in returning prime-time series.

Secrecy surrounds some of the season-opening scenarios, such as the fate of Pam Ewing on “Dallas,” who was last seen in a fiery car crash. While Victoria Principal has departed the long-running CBS soap, a spokesman for the production company said it’s “not safe to say” that the Ewings will be mourning Pam’s death.

One passing that is certain is on NBC’s “Valerie,” where Valerie Harper’s character is being killed off to explain the actress’s firing after a feud over money and other issues. Sandy Duncan will take over the lead role of the series as Valerie’s divorced sister-in-law. The show, now called “Valerie’s Family,” will begin nine months after the death.

What about the resurrections? That’s the best way to describe the returns of private eye Tom Magnum and Inspector Sledge Hammer, who apparently had met their TV makers earlier this year. But much to the producers’ surprise, CBS renewed “Magnum, P.I.” and ABC did the same with “Sledge Hammer!,” so back they come.

The reasons for those two changes is obvious--but why do producers alter their shows even when they are scoring well in the ratings?

Caryn Mandabach, supervising executive for the Carsey-Werner Co., which produces “The Cosby Show,” explained that changes keep a show “fresh and interesting.”

“You can learn from your audience and use that feedback to perfect the show,” she said. “As a work-in-progress, we don’t have to do it all in a day, thankfully.”

Here is a rundown on noteworthy changes to be made in series returning for the 1987-88 season, with premiere dates listed parenthetically.

NBC

TV’s top gun, “The Cosby Show,” will be losing a daughter (Lisa Bonet, who will star in her own sitcom, “A Different World”) and gaining a son-in-law. As the season opens (Sept. 24), Cliff’s oldest daughter Sondra (Sabrina Le Beauf) and her Princeton boyfriend Elvin (Geoffrey Owens) will be returning from their honeymoon.

Why no wedding wingding? According to Mandabach, “we get more value from not showing it.” Claiming that she didn’t want to spoil the premiere for viewers, Mandabach simply said the Huxtables “will be surprised about how their little girl has changed.”

Over on “Cheers,” the question is whether a Ted Danson-Kirstie Alley brew will recall memories of the sexual tension that Danson once generated with the departed Shelley Long, whose Diane Chambers is off writing a novel. Alley will play the bar’s new manager, Rebecca Howe, a beguiling brunette who isn’t swept away by Sam Malone’s seductive charms, to his surprise.

As for the other “Cheers” regulars, Norm (George Wendt) will find a full-time job, Carla (Rhea Perlman, pregnant in real life) will have another child and legitimize it, and Cliff (John Ratzenberger), the network says, will take a “quantum leap toward manhood” (Sept. 24).

Already moved from Thursday to Sunday night, a new time slot is not the sole change for “Family Ties.” The comedy’s hourlong premiere, which aired Sunday, introduced Alex’s (Michael J. Fox) new girlfriend, a psychology student (Courteney Cox).

NBC’s longest-running series, “The Facts of Life,” returns for its ninth season (Sept. 26) with the addition of Australian actress Sherrie Krenn as exchange student Pippa McKenna. Among the regulars, aspiring actress Tootie (Kim Fields) will get engaged.

Speaking of engagements, “Miami Vice” plans to stress “life-changing circumstances” for its dapper detectives Sonny Crockett (Don Johnson) and Ricardo Tubbs (Philip Michael Thomas). Just what does that mean? Well, Crockett will marry a rock star, while Tubbs will question his status on the vice squad (Sept. 25).

At “L.A. Law,” the firm of McKenzie, Brackman, Chaney & Kuzak has strengthened its staff. Blair Underwood will join the series as Jonathan Rollins, a Haaa -vard man who takes on cases that involve the entertainment industry. And fans of Arnie Becker (Corbin Bernsen) take note: The womanizing divorce attorney will be bought in a charity auction on the season debut (Oct. 15) by a kinky character played by Laura Johnson, formerly of “Falcon Crest” and, coincidentally, the wife of series regular Harry Hamlin.

In a bid to build its comparatively small audience, “Crime Story” will have more self-contained episodes, more women as guest stars and a stronger emphasis on Lt. Torello’s (Dennis Farina) crimebusters (Sept. 22).

On the cliffhanging finale of “St. Elsewhere,” a wrecking ball was about to demolish dilapidated St. Eligius Hospital. As the doctors resume their rounds Wednesday in a remodeled facility, Ronny Cox will come aboard to make life miserable for them as an abrasive, cost-cutting administrator in charge of keeping the freshly scrubbed hospital financially afloat. Cox will temporarily clash with chief of staff Donald Westphall (Ed Flanders), who will leave after three episodes.

Andy Griffith’s “Matlock” will bring down the gavel on a second season (Sept. 22) with two new regulars: Nancy Stafford as a junior partner (replacing Linda Purl, who played Griffith’s daughter) and Kari Lizer as an overeager law clerk. Julie Sommars will have a recurring role as an assistant district attorney.

In all the commotion over Valerie Harper’s dismissal on “Valerie’s Family,” not much ado was made over the addition of one other cast member. Willard Scott, the “Today” show weatherman, will bring his sunny disposition to the series as Peter Poole, the Hogans’ next-door neighbor (Sept. 21).

CBS

Unlike “The Cosby Show,” the producers of “Newhart” favor on-air nuptials. With an eye on the November ratings sweeps, the series plans a big wedding for Stephanie (Julia Duffy) and Michael (Peter Scolari). New episodes begin tonight.

On “My Sister Sam,” which has moved to Saturdays, there will be romance as well. In a two-part season start (Oct. 3), free-lance photographer Sam (Pam Dawber) will click with neighbor Jack (David Naughton) after she learns that her boyfriend has decided to marry someone else.

Meanwhile, Tom Magnum (Tom Selleck) has more important matters on his mind--survival, namely--as “Magnum, P.I.” launches its eighth season. Magnum, fans will recall, was on his death bed after being gunned down in last year’s finale, titled “Limbo.” A repeat of that episode, due Sept. 30, will have new footage that will resolve Magnum’s “out-of-body experience.” Co-executive producer Chas. Floyd Johnson said it “may provide clues for the discerning viewer and add a possible key or thread to the entire season.” With the series most likely drawing to a close this season, Selleck has vowed that his character will have a fitting farewell (Oct. 7).

After bidding farewell to Victoria Principal, the cast of “Dallas” will welcome several newcomers in 1987. Among them are Jack Scalia as an entrepreneur who helps Sue Ellen (Linda Gray) in her business affairs; Bert Remsen as a crusty ex-wildcatter who bears a resemblance to Digger Barnes, and Andrew Stevens as a charismatic con man who assists J. R. (Larry Hagman). The serial begins with a two-hour installment Sept. 25.

A long list of familiar faces will guest on CBS’ other long-running soap, “Falcon Crest.” The roster includes Leslie Caron, Ed Marinaro, Ursula Andress, Eddie Albert, Eve Arden, Buck Henry, Rod Taylor and Lauren Hutton, among others (Oct. 2).

While “Knots Landing” has lost Peter Hollister (Hunt Block), who was murdered last May, it will gain the services of Red Buttons and Michael York. The latter will play an old boyfriend of Abby’s (Sept. 24).

And what of “Cagney & Lacey,” the network’s top Emmy Award winner? Christine (Sharon Gless) will continue her treatment at Alcoholics Anonymous, lose her boyfriend, David Keeler (Stephen Macht) and start a new relationship. Mary Beth (Tyne Daly) will have trouble at home with rebellious Harvey Jr., who becomes fascinated with the military. Back at the precinct, Petrie (Carl Lumbly) will leave the series when he’s promoted out of the 14th and Isbecki (Martin Kove) will have a new partner, played by Merry Clayton (Sept. 21).

ABC

“Spenser: For Hire,” the Robert Urich detective series that in two years has bounced around more than most bad checks, turns up on Sunday this month opposite “Family Ties” and “Murder, She Wrote.” With such murderous competition, the show’s producers recruited Barbara Stock to return as the Boston-based gumshoe’s girlfiend, Susan Silverman (Sept. 27).

In the final episode of “Sledge Hammer!” last season, time apparently had run out for tough-talking cop Sledge (David Rasche). The ratings-hammered hero had blown himself up while trying to dismantle a nuclear bomb. Rest assured executive producer Alan Spencer devised a way to keep the comedy series ticking. It begins anew Thursday. Trust him.

On Tuesdays, Judith Light’s gloss will endure on “Who’s the Boss?” (Sept. 22). Angela (Light) will re-evaluate her feelings for housekeeper Tony (Tony Danza) after he is visited by an amorous old friend (former soap star Kristian Alfonso).

“Perfect Strangers” will employ a new work setting for Larry (Mark Linn-Baker) and Balki (Bronson Pinchot). The cousins will stop the presses at a newspaper that hires Larry as a cub reporter and puts Balki in the mailroom (Sept. 23).

Moved to Wednesdays at 10 p.m., “Dynasty” will add a regular to be played by newcomer James Healey. In the season debut Sept. 23, Healey will plunge into the plot by rescuing Alexis (Joan Collins), who accidentally drove her car off a bridge in May.

On “Ohara,” the crime-fighting cop (Pat Morita) will have a new partner. He will be played by Robert Clohessy, formerly of “Hill Street Blues.” They will be assigned to a special task force headed by Rachel Ticotin (Oct. 3).

And last, but by no means least, what will happen on “Moonlighting,” ABC’s hottest hit?

A publicist for the series said expectant Cybill Shepherd will appear in most, if not all, of the episodes this fall. Maddie (Shepherd) will be off visiting her parents, while the Blue Moon agency’s cases will be handled by David (Bruce Willis) and clerk-cum-P.I. Bert Viola (Curtis Armstrong).

Can David, Bert and Ms. Dipesto (Allyce Beasley) hold down the shop without Maddie? Will the show’s lofty ratings hold up in the meantime?

Stay tuned.