The National Highway Traffic Safety Administration has ramped up an investigation into reports of fires sparked by electrical systems in driver's-side doors, mostly on General Motors vehicles.
According to Detroit News, both NHTSA and GM have received numerous complaints about the problem. Consumers have filed 28 reports of door fires and 88 complaints of melting and erratic switches with NHTSA. GM has received 167 complaints.
In a letter sent to NHTSA earlier this year, GM says that the problem tends to involve window, lock, and other switches found on driver's-side doors. Evidence suggests that the switches begin to function erratically before finally failing to work at all. In some case, the faulty wiring can cause heat, smoke, and occasionally, set the surrounding plastic on fire.
Perhaps most worryingly, some of the reports indicate that fire broke out while vehicles weren't running or even occupied.
The problem may be linked to the power master switch found on vehicles using the GMT 360 mid-size SUV platform. That list of vehicles includes 2006 and 2007 models of the Buick Rainier, Chevrolet Trailblazer, GMC Envoy, Isuzu Ascender, and Saab 9-7x.
Interestingly, these same models suffered from problems with their fuel gauges, which GM agreed to help fix late last year.
NHTSA's investigation began with 340,000 Trailblazer models. There's no word on how many vehicles are now included in NHTSA's expanded probe.
We'll keep you posted as the investigation continues.