"Sunburn" may not be the suspense-and-action-packed comedy it was intended to be, but it is a chance to see Farrah Fawcett-Majors, her hair, and about a million different costumes, or portions thereof. And to some movies-goers, that's enough.

Maybe the glow of all that golden wonderfulness has blinded Fawcett-Majors to the transparent surfaces of the scripts she's been skating on. It would seem that after the box office slide that "Somebody Killed Her Husband" took last year, she would know thin ice when she saw it.

But here we go again.

This time it's a $5 million insurance claim filed by the bereaved family of a wealthy Acapulco businessman who is last seen driving his Cadillac through a rickety bar and a bunch of unsavory characters before bursting into flames. The family says it's an accidental death; the company president says it isn't and sends an ace if unorthodox detective (played by Charles Grodin) to investigate the claim.

Grodin in turn hires a professional model (Fawcett-Majors) to provide him a cover by pretending to be his wife on a fun-filled vacation to Acapulco while he pals around with Art Carney as his aging sidekick and tries to solve the case.

Despite the overwrought caricatures of a nymphomaniacal attorney's wife, an alcoholic playboy and a mob hitman filling up the set, not much goes on besides the Acapulco scenery between costume changes.

That pace gives the characters plenty of time to decide who they'd like to imitate. Fawcett-Majors can't seem to decide between attempting a screwy but charming madcap and a truly adorable ice-cream sundae - whose developing romance with Grodin seems inevitable from the start. Grodin wavers between an uptight Robert Redford and total blandout, and Carney tries gamely to limp through a concoction of action and campy dialogue reminiscent of James Bond or Batman. The heroes out to rescue the heroine through a hail of gunfie: Grodin: "What are you doing?" Carney: "Thinking." (Grodin: Thinking what?" Carney: "I think they spotted us.")

While the plot staggers toward a resolution, the story seems increasingly to serve as an excuse for Farrah's diving scene, the Big Chase Scene, the oh-my-God-it's-love scene, and the rescue scene.

The chase scene's not bad.

But then life for Farrah Fawcett-Majors fans, as for the rest of us, is a series of trade-offs. In exchange for having to listen to Carney tell Grodin in deadly seriousness that "The underworld doesn't play tiddlywinks," there is Farrah in her evening gown, what there is of it. After the makeshift suspense of watching her tap her first telephone, we get to see her in her diving outfit. What there is of that. There is also a very moving chihuahua who plays his entire scene in a coat pocket.