Banks Hoggins O'Shea/FCB has produced the £1.5 million national TV initiative.
It extends the brand's "generating energy for everyone" message introduced last year, but attempts to give it a more human feel.
PHD is planning and buying media for the campaign, which breaks on Friday 9 May.
The strategy is reminiscent of the long-running approach used by Weetabix's former agency, Lowe. It is designed to sustain the natural goodness message Weetabix has used since its launch 70 years ago.
The 30-second spot underscores the claim by featuring a young boy running through a church courtyard to join a bell-ringing practice session.
As the bells ring out, their tune begins to take shape. It turns out to be the theme from The A-Team - much to the puzzlement of a passer-by walking his dog.
The film was written by Bryn Attewell, art directed by Mark Robinson and directed by Mark Mylod through Tomboy Films.
Mylod, whose credits include The Fast Show, the Royle Family and Ali G Indahouse, was chosen to direct the commercial following his work on the agency's debut TV campaign for Ready Brek last autumn.
Weetabix, which vies with Kellogg's Corn Flakes for leadership of the UK breakfast cereal market, has been working to sustain sales at a time when busy lifestyles have led to more people eating on the way to work or at the office.