DETROIT (AP) — U.S. safety regulators have determined that two recalls of older General Motors vehicles for headlight failures were big enough to take care of the problem. The National Highway Traffic Safety Administration says in documents posted Friday that it’s closing a 4-year-old investigation without seeking any more recalls. The recalls were due to the failure of headlamp controls that caused the vehicles to lose low-beam and daytime running lights. Investigators looked into whether all vehicles with the same controls should be recalled.