KISSIMMEE, Florida (CNN) -- Early this year, Laura Hernandez nudged her husband, Nestor Oyola, as he slept in their Kissimmee home and asked him to put the Ford Expedition he had bought her the day before into the garage.
She did not want to risk leaving it on the street, where it might be vandalized.
"That was my dream, to have a Ford Expedition," she recalled to CNN about the $22,000 Eddie Bauer 2001 model SUV -- green with gold trim and leather seats.
Oyola moved the Expedition and they went to sleep.
After years of sharing a single car, the couple -- who moved five years ago to the United States from Puerto Rico -- were finally living the American dream: They owned two vehicles and their home.
At 5 the next morning, half an hour after her husband had driven his SUV to work, Hernandez was awakened by barking from Chakuil, their Chihuahua mix.
"He saved our lives," said Hernandez, who smelled smoke and roused her 15-year-old daughter, Rotsenmary.
They had time to grab only the dog and their pet birds before flames spread from the garage and engulfed the house.
Rotsenmary suffered a second-degree burn to her left leg; the charred remains of their 6-month-old cat -- Beethoven -- were found in a corner; the vehicle, the house and its contents were a total loss.
A fire investigator, hired by their auto insurance company, said the blaze was caused by a cruise-control deactivation switch in the SU
V -- a type of switch that Ford installed in millions of its vehicles from 1992 until 2003.
An Iowa family is suing Ford over the switch, claiming it was the likely cause of a fire in the family's 1996 F-150 parked in an attached garage that spread to their house. A 74-year-old woman died in the fire and the house was destroyed. Ford, however, says the fire did not originate in the F-150. (Full story)
Several fire investigators hired by major insurance companies and auto engineers consulted by CNN say the switch is causing some Ford vehicles to ignite.
The $20.57 switch shuts off the cruise control when the driver firmly steps on the brakes. The switch is located under the hood of the vehicle and is attached to the brake master cylinder on one end and wired to the cruise control on the other.
On most of its models, Ford designed the switch to be powered -- or "hot" -- at all times, even when the vehicle is off and the key is removed from the ignition.
Inside the switch, a thin film barrier separates brake fluid from the switch's electrical components. Investigators say fires can occur when the film cracks and brake fluid from the master cylinder seeps into the electrical side of the switch.
Ford has already recalled more than 1 million vehicles in two separate recalls to replace the switch.
The first recall was in May 1999, affecting 279,000 Crown Victorias, Grand Marquises and Town Cars for model years 1992 and 1993. The second, issued in January 2005, affected 792,000 vehicles, including model year 2001 F-Series SuperCrews and 2000 Expeditions, Navigators and F-150 pickups.
But a Ford document obtained by CNN shows the same or similar switch was installed in a total of 16 million vehicles, far beyond what was recalled. Those vehicles include:
# Mark VII/VIII from 1994-1998
# Taurus/Sable and Taurus SHO 2.3 L 1993-1995
# Econoline 1992-2003
# F-Series 1993-2003
# Windstar 1994-2003
# Explorer without IVD 1995-2003
# Explorer Sport/Sport Trac 2002-2003
# Expedition 1997-2003
# Ranger 1995-2003
In March, the National Highway Traffic Safety Administration opened an expanded investigation into more than 3.7 million of the vehicles.
NHTSA says it has received 559 complaints of spontaneous fires, 253 of them in unrecalled models, and its latest investigation includes the 1995 model years of the F-150, Expedition and Lincoln Navigator vehicles.
Ford says it has initiated its own investigation and is cooperating with the NHTSA probe.
"We have identified specific populations of vehicles in which the speed-control deactivation switches have had increasing rates of failures and fires," said Ford spokeswoman Kristen Kinley in a written response to questions submitted by CNN.
"When we have seen the fire reports increasing, we have recalled those vehicles and replaced those switches. Ford has used the basic switch design in a large number of vehicles and the risk of fire related to the switch is much different in those certain populations that we have recalled."
She added, "It is important to understand that all speed control systems are not identical in Ford vehicles. ... In those populations with an increasing fire report rate, we stopped using the switch through the recall process. ... The switch has performed well in many models for many years."
In another statement to CNN, Kinley said "we have been asked why we have not expanded the recall. The last thing we want to do is make an important safety decision on incorrect or incomplete information."
Kinley also said, "We have not determined at this time that there is a defect with the switch, but for reasons we still do not understand the switch is failing ... and we are trying to understand why."
Ford no longer uses switch
But, in a recall notice to owners of 2000 F-150s, Expeditions, Navigators and 2001 F-150 SuperCrews, the company seemed less equivocal about the switch. The "switch may overheat, smoke or burn which could result in an underhood fire," it said. "This condition may occur either when the vehicle is parked or when it is being operated, even if the speed control is not in use."
The company stopped using the switch altogether as of the 2004 year model, and is now using a new design.
Meanwhile, the Oyola-Hernandez family has hired a lawyer to reach a financial settlement with Ford but have not filed a lawsuit against the company.
The company says it has not yet investigated their auto insurance claim, but notes that the insurance industry reports about 100,000 noncollision fires per year involving nearly all makes and models sold.
"Simply because we have allegations of fire doesn't mean they are necessarily linked to the speed-control deactivation switch," Kinley said.
The charred remains of their house were recently demolished. But, the family has not been able to rebuild.
After the fire, they moved in with Hernandez's mother, who lives nearby. Since then, after reinstating their home insurance, they have moved into a rented house. Their insurance company sent them $120,000 but rebuilding their home is estimated to cost $185,000. They are hoping Ford will reimburse them for the difference.
They are, once again, a one-car family. This one also is a Ford -- a 1997 Explorer -- and it, too, contains the suspect switch, which has not been recalled. The family parks it on the street instead of the garage.
CNN Investigative Producer Pia Malbran contributed to this story