Highway safety administrator Raymond A. Peck has begun his top priority campaign to promote the voluntary use of seat belts by the nation's motorists--but so far without the fanfare and the White House salute that he was counting on.

Peck wanted a full-dress press conference with President Reagan and Transportation Secretary Drew Lewis to launch a nationwide "buckle up" campaign involving private companies, schools, the media and sports and entertainment celebrities.

He presumably will still get the fanfare, but after months of unexplained delay, there is no green light from the White House. So Peck has started the program anyway.

One of the National Highway Traffic Safety Administration's first moves is a recent warning to its employes to wear auto safety belts when on government business or face the possibility of reprimands in their personnel files, a move that has caused grumbling within the agency about heavy-handed "voluntary" coercion. (NHTSA says the requirement has always existed but is now being enforced. The reprimand would apply to employes involved in accidents.)

The agency has asked Congress to authorize a shift of funds from other NHTSA programs into the new campaign. And agency officials continue to seek public support for it.

Peck promised a nationwide publicity blitz on seat belts last October, when he terminated NHTSA's "passive restraint" program to equip cars with air bags or belts that closed automatically.

Peck said he had concluded that the automakers wouldn't install air bags and that automatic belts would be no more effective than the belts and shoulder harnesses that are now in cars. According to NHTSA, only 11 percent of motorists wear conventional seat belts and harnesses.

Auto insurance groups and congressional supporters of "passive restraints" continue to oppose Peck's decision, saying he failed to recognize the benefits of automatic belts.

Meanwhile, Peck and his public affairs chief, Edmund Pinto, are relying on public education as their strongest safety weapon. Pinto, coordinator of the campaign, said the agency is receiving much outside support.

He keeps a running count of companies that are stepping up voluntary efforts to increase safety belt use, such as the major steel company that checked employes entering a company parking lot and gave $10 bills to those who were buckled up.

Most of the $8 million that will finance NHTSA's role in the program is unspent money appropriated for the agency in the past for other programs. For example, under Peck, NHTSA has canceled a $1.6 million project to deal with unsafe driving by seeking measures to combat "major behavioral causes of accidents" and by developing automated speed enforcement techniques.

NHTSA has reclaimed $860,000 earmarked for its "research safety vehicles," special test vehicles incorporating new occupant protection measures, and is putting that into the safety belt campaign, as well as $454,000 originally intended to study the effect of drug use on driving safety.