WASHINGTON, D.C. --- The National Highway Traffic Safety Administration (NHTSA) said this week it has launched a preliminary investigation into the safety of 1.7 million Ford Windstar vans equipped with the same cruise control deactivation switch that's led to the recall of nearly 10 million other Ford vehicles.

The federal agency announced the investigation after receiving complaints of 130 engine fires, including 36 in the past year. A total of 33 of the complaints said the vehicle was parked at the time of the fire. Two of the fires reportedly caused structural damage to homes.

Before issuing an official recall of the Windstar, NHTSA must first conduct an investigation of the complaints to see whether a recall is warranted.

Windstar vans from the 1995-2003 model years are part of at least 6 million Ford vehicles with the cruise control deactivation switch that haven't been recalled, the Detroit News reported. Ford spokeswoman Jennifer Moore told the newspaper that the switches in the Windstar vans were installed differently than those in the recalled vehicles. In the vans, the switches don't have electrical power running to them at all times, unlike switches in the recalled vehicles.

"We're cooperating with NHTSA," Moore told the Detroit News. "We've continued to monitor the field performance of our vehicles and we don't believe at this time there is an elevated risk of fire." She added that Ford didn't know the cause of the fires cited in the complaints filed with NHTSA.

The $21 switches, manufactured by Texas Instruments, were installed in more than 16 million Ford vehicles over a decade before Ford stopping using them in 2002. About 40 percent of the recalled vehicles have been repaired. That leaves a little less than 4 million that still need to be fixed.