Seidel Chevrolet, a car dealership launched here in the waning days of the 1973-74 energy crisis, has been ranked the 15th largest black-owned business in the country by the magazine, Black Enterprise.

The magazine, which has been compiling its listing annually for five years, reported that the Landover dealership owned by John Seidel had sales of $10.4 million in 1976, making it the third largest dealership on the list - behind Cadillac firms in New York and Chicago. It is Seidel's first appearance among the top 100.

Other Washington firms on the list are veterans of the rankings. They include:

Capitol City Liquor Co., Inc., a seven-year-old liquor wholesaling operating headed by Chester C. Carter. With sales of $10.5 million in 1976, it was the 14th largest among the top 100. It was 10th last year.

Jones & Arts Construction Co., the paving and construction firm of Carl D. Jones and James Artis. With revenues of $5.4 million it rose from 58th to 46th on the list.

Syphax Enterprises, an Arlington construction and apartment management company headed by William T. Syphax. The firm had revenues of $4.2 million, but took a plunge from 26th to 68th. Cold weather this winter had affected construction operations, Syphax said yesterday.

Among black-owned banks, the Industrial Bank of Washington rose from fifth to fourth largest, with assests of $41.1 million, and United National Bank was 10th with assets of $27.8 million.

Independence Federal Savings and Loan Association was fifth again among S & Ls, with assets of $35.5 million. Community Federal Savings and Loan Association rose from 27th to 17th, with assets of $11.3 million.

Nationally, the Motown Industries entertainment conglomerate of Berry Gordy Jr. was ranked first in revenues among the top black-owned companies. It's sales stood at $50 million in 1976, up from $43.5 million the year before.

Earl G. Graves, publisher of the New York-based Black Enterprise, said at a luncheon in Atlanta that total sales of the top 100 were up by nearly a fourth, from $623.9 million to $775.2 million. (In contrast, three lowest-ranking corporation on Fortune 500's listing of the largest industrials, Foxboro Co., an instruments firm, had sales of $327.7 million last year.)

Graves said that car dealerships still account for the largest single group among the 100, with 37 this year, compared with 26 last year.

"Jack" Seidel, 48, a former general manager of the Blank Pontiac dealership, began his own Chevy dealership at a time when three other black-owned car firms here had failed or were about to go under. Currently, only one other black-owned new car company - McLaughlin Olds - is operating here, according to a spokesman for a local auto dealers group.

Seidel said his climb to the top 100 has had its setbacks, including the period when car prices were raised in 1975. His business "didn't really start rolling here until about six months ago," he said. "The last six months have definitely improved."