In the endearing zoology of Congress, just when you've pigeonholed the the bomb-throwers and the Babbitts, along comes a spoiler who turn the theories upside down.

Take John W. Warner, the junior Republican senator form Virginia, who usually sides with the crusty conservatives in the big policy debates.

Warner, a former Navy secretary, is big on the military. He squawks about federal medding in private business. He doesn't like environmental zealots holding up progress. He's hustling in Congress to help the ailing U.S. auto industry and, in private life, has pledged t buy no foreign-made car.

So much for the pigeonhole. The other side of this is that Warner has, in recent weeks, almost single-handedly revived an issue once given up for dead -- the controversial automobile airbag. r

After a good deal of lobbying and arm-twisting by Warner, a Senate-House conference committee of which he is a member has reached an agreement that breathes new life into the airbag.

Airbag supporters and auto safety lobbyists are not elated with the conferees' work, but they generally give Warner credit for saving the day.

"The conferees postponed the standard for a year," said Joan Claybrook, head of the National Highway Traffic Safety Administration (NHTSA), "but what Warner got was substantial. He did a fantastic job. Spent hours on this, called in the auto companies, listened to all sides, then persuaded the conference."

If Warner's compromise is adopted by the House and Senate -- still an iffy proposition -- it would mean that in 1983, American consumers would have the chance to buy cars equipped with airbags.

Warner said in an interview this week that, after he cut through all the debate, it wasn't very difficult to come out for the airbag option. "I've been on a team here fighting for the auto industry and now they ask me frankly how I can be helping them and then load this airbag thing on them," he said.

"Well, we're in mourning for 52 hostages being held in Iran, yet about 52,000 American lose their lives on the highway every year. That's an astonishing record and I think the airbag can help reduce those fatalities. Nobody will be forced to use the airbag, but it will be available in some cars by 1983 under this agreement."

Department of Transportation tests and a brief experience with about 10,000 General Motor Corp. cars in the mid-1970s have shown a high degree of crash protection when the airbag, which automatically inflates on impact, is used.

But as the airbag debate has gone on over the years, very few congressional conservatives or friends of the auto industry have supported the idea of equipping cars with the quick-inflating devices.

The auto industry has resisted DOT efforts to promote the airbag, and government critics like to depict the "passive restraint," as it is called, as an example of wrongful bureaucratic meddling with Detroit.

In 1977, DOT put the industry on notice that beginning in 1982, new cars would have to have some type of passive restraint to protect front-seat passengers. It could be an automatically locking belt or an airbag.

But even though the bags have shown a higher level of crash protection, automakers don't like the idea of the added cost they would entail.

By an overwhelming vote last December, the House adopted an amendment to the NHTSA authorization, banning NHTSA from enforcing any standard that did not allow either consumer or car dealer to order cars with manual safety belts of the type now in use.

The amendment's sponsor, Rep. David Stockman (R-Mich.), insisted this provided consumers with a choice, but critics said that, given the resistance to airbags, the amendment's effect would be to eliminate them.

The Senate, meanwhile, adopted its NHTSA authorization with no changes in the passive restraint rule. That left conferees with the Stockman choice, a variation on it or nothing at all.

That's when Warner came in.

"The guts of this," Warner said, "is that we have slipped a year, from 1982 to 1983, but by 1983 every company is going to have an airbag resteaint system in at least one of its car lines. The consumer is going to have a range of choices, and I think there is going to be a lot of interest in the airbag because it works."

Warner was unsuccessful in his efforts to require the companies to produce a minimum number of airbag-equipped cars each year.

"the other thing here is that we are forcing the foreign companies to get involved in safety in our country. With the country moving to more small cars and highway fatalities likely to increase, it is now or never for the airbag." Warner said.

"I think it is going to be a tremendous sales force, and the American companies are far ahead of most foreign producers on airbag technology. I just hope the industry will be passive itself when the issue is back before the House and Senate."