DAYTONA BEACH, Fla. (AP) _ Dale Earnhardt was fined $5,000 and placed on probation for the rest of the 1986 Winston Cup season because of reckless driving at Sunday's Miller 400 in Richmond, Va., NASCAR said Monday.

Earnhardt was leading the race with three laps remaining when Darrell Waltrip was passing him on the back straightaway at the Richmond Fairgrounds Raceway.

Officials at the National Association of Stock Car Auto Racing, who reviewed films of the final laps, said Earnhardt made an irresponsible move in hitting Waltrip. The resulting wreck extensively damaged both men's cars and those of several other drivers. No one was injured.

Kyle Petty maneuvered his car through the crash for the victory. Joe Ruttman finished second with Earnhardt third.

Earnhardt, in a phone interview from Charlotte, N.C., also said that his move was not irresponsible, but was strictly an accident.

''I misjudged the distance between the cars. I turned him sideways,'' he said. ''It's my fault. I'm not denying that. I made a mistake and hit him.

''But I don't think I'm guilty of reckless driving or wrecking somebody purposely. It was an accident.''

''There is a fine line between hard racing and reckless driving, and Earnhardt clearly stepped over that line Sunday,'' said Bill Gazaway, NASCAR's vice president for competition. ''We simply cannot tolerate or condone such actions. We must preserve the integrity of our sport.''

Earnhardt was fined $5,000, put under a $10,000 bond and placed on probation for the remainder of the 1986 season, Gazaway said.

NASCAR spokesman Andy Hall said the bond was due immediately, but ''that money is subject to refund, depending on how Earnhardt lives up to the conditions of his probation.''

Earnhardt said he did not know what the conditions of the probation were, because he had not yet been informed of the fine or probation by NASCAR. He said he learned of his penalties only through the media. He added, however, that he planned to appeal the fine and that he expected a hearing to be held in his case, at an undetermined date.