Customers who had stayed away from suburban malls because of the gasoline shortage apparently resumed their Saturday shopping rituals yesterday as area gasoline lines continued to shrink.

The American Automobile Association estimated that 83 percent of area service stations were open yesterday - the highest percentage for a Saturday in weeks. But the AAA predicted that only nine percent would be open today.

Most gasoline lines were reported short yesterday, and merchants at shopping malls said there appeared to be more shoppers than on recent weekends.

"It's like Christmas out here," said Springfield Mall spokeswoman Joanne Roberts. "I would say we're having an exceptionally busy day."

Terry Cephos, assistant manager of Kids in gear, a children's clothing shop at Landover Mall, said yesterday that business "is definitely better than it's been. It's started to grow in the past week."

"We've had more people in here in the last two days than in months," said Vi Sokol, manager of L. Frank, a women's clothing store at Landmark Shopping center. "I've had customers say they're going crazy staying at home and now that there's gas they're going shopping."

I got gas this morning so I came out to Landmark," said Sharon Smith of Alexandria. She said she had drastically curtailed her trips because of the fuel crisis.

Numerous merchants said yesterday that although business seems to be improving, they are fearful of the impact of the presidential order that takes effect Monday, requiring nonresidential air conditioning to be set no lower than 78 degrees.

"We've had to put a lot of summer merchandise on sale earlier than usual," said one Hecht Co. saleswoman, "and now we're starting to get our fall and winter stuff in. But who's going to buy a winter coat when it's 80 degrees in the store?"

L. Frank manager Sokol agreed. "First there's no gas, and that really hurt business, and now they're saying we have to turn up the thermostat. Mr. Carter's just got us in a mess. He's doing everything against business."

Other salesmen said they don't expect hotter store temperatures to affect sales.

"Business in large appliances hasn't been off much even recently," said one Sears salesman at Landmark, leaning against a bank of washing machines and watching a steady stream of customers getting off an escalator. "If a washing machine breaks, well, people are going to go out and buy a new one," he said.

This morning when I opened the store at 9 a.m., there were already people waiting," said Teresa Pope, a sales clerk at The Gap at Landmark, which is near Alexandria's densely-populated "Condo Canyon."

James McCullough, manager of Bloomingdales at Tysons Corner, described yesterday's business as terrific.

"Three weeks ago Saturday was our toughest day yet," said McCullough. "The new store temperature thing certainly won't help business. I think people are going to spend a lot less time shopping. They're going to want to get in and out fast."