Federal safety regulators have opened an investigation into Dodge and Chrysler minivans from the 2005 model year because the headlights can fail without warning.
The National Highway Traffic Safety Administration said on its website that 622,817 Dodge Caravan and Chrysler Town and Country minivans could be affected by the problem.
The agency says more than 1,500 owners have complained to Chrysler or the government. Two crashes and one minor injury were reported to Chrysler. In addition, 14,208 warranty claims that may be related to the problem have been reported by Chrysler.
Documents filed on the agency's website say that the headlights can go out while the vans are moving, but the bright lights are always available. Investigators are looking at headlamp switches as a possible cause.
NHTSA said that toggling the headlight switch back and forth usually can turn the lights back on, according to complaints filed with the agency. Chrysler also has received complaints of dimming or flickering headlights. The number of complaints is declining, according to the company's data.
The records say that one driver reported to Chrysler that they hit a deer when the lights went out, while another drove into a ditch.
NHTSA said it will analyze consumer complaints and Chrysler's technical information.
"Additional testing will be conducted to evaluate possible root causes of the alleged defect and will include analysis of suspect components collected from the field," the agency said.
NHTSA opened the investigation on Tuesday, it said in documents posted on the website during the weekend.
An investigation could lead to a recall, although it doesn't always mean that one will be ordered.