The National Highway Traffic Safety Administration (NHTSA) is conducting an investigation into approximately 103,107 2005-2007 Chevrolet Corvette models based on 95 reports that both low-beam headlights stopped working simultaneously. A preliminary investigation was opened in May after 30 reports, and the investigation was upgraded to a full engineering analysis as the number of complaints rose to 95.
General Motors says this defect is caused by a fractured circuit wire in the underhood bussed electric center (UBEC) which is similar to a fuse box. Apparently, the UBEC is in a high heat area of the engine compartment which makes it more susceptible to stress. Owners have complained that the loss of the low-beam light happens after five to 30 minutes of driving. The problem is intermittent, with low-beam functionality returning after the car has been parked in some cases. This problem does not affect the high-beam headlights.
GM is continuing to cooperate with the investigation, and if NHTSA finds that this defect poses a risk to safety after the engineering analysis then they will ask GM to recall the vehicles. For now, the NHTSA investigation is only for 2005-2007 Corvette vehicles, but NHTSA has also received four complaints of the same problem in 2008 Corvette models.
Sources: NHTSA, The Detroit News