WASHINGTON (Reuters) - Ford Motor Co is expanding its largest ever recall -- involving faulty cruise control deactivation switches that have caused fires -- by 4.5 million vehicles, regulators and company officials said on Tuesday.

Ford Motor Company employees place windshields in the new 2002 Ford Explorer sport utility vehicle that is in production at the Ford Assembly Plant in Louisville, Kentucky, April 4, 2001. REUTERS/John Sommers II

The action effectively closes out a 10-year saga over the switches made by Texas Instruments that has led to more than a half-dozen recalls at Ford covering 14 million registered vehicles, the automaker said in a letter to the National Highway Traffic Safety Administration (NHTSA).

The government added two million vehicles to the Ford total, factoring in models not believed to be on the road. Affected vehicles should be taken to Ford dealers to be fixed.

“While the data show the majority of the vehicles being recalled do not pose a significant safety risk, we are recalling the vehicles to reassure consumers and eliminate any future concerns,” Ford said in a statement.

Ford did not provide information on how much the latest recall would cost the company. It stopped using Texas Instrument switches in 2003.

Texas Instruments said in a statement that a former business unit designed and manufactured the switch to “meet and exceed” Ford specifications, and is not the “root cause” of fires. A 2006 NHTSA investigation, Texas Instruments said, concluded that multiple factors contributed to the fires.

It was the second major recall in as many weeks for the auto industry. On September 30, Toyota Motor Corp said it would recall approximately 3.8 million vehicles in the United States because of floor mats that can come loose and force down the accelerator.

The problem at Toyota is suspected in crashes that have killed five people.

Ford and Toyota have been two of the stronger performers during the industry’s severe sales slump, although their U.S. businesses remain off compared to last year.

U.S. and foreign automakers are emphasizing quality more than ever as consumers seek economy and reliability with fuel prices high and recession and tight credit eroding the pool of potential buyers.

NHTSA on Tuesday alerted owners of more than a half-dozen truck and van models sold in the United States and U.S. territories of potential fire hazards linked to flawed switches in Ford vehicles.

In a warning to consumers, government safety officials investigating the switches said leaking fluid can overheat and potentially cause fires even when the ignition is off. There have been fires reported over the years and some minor injuries, Ford said.

“I urge consumers to pay attention to this warning and bring the affected models in to have them repaired as soon as possible,” Transportation Secretary Ray LaHood said in a statement.

Ford said in its letter to NHTSA that it had noticed an increasing number of leaking switches on Ford Windstar vans and a small number of switch fires had been reported. Ford said it was unaware of any accidents or injuries involving the Windstar fires.

Ford decided to recall the 1.1 million Windstar minivans made between 1995-2003. It included remaining models not covered in previous recalls even though there was no finding that the switches in those vehicles were unsafe.

“Ford is taking this action on all of these vehicles to address possible ongoing customer lack of confidence in vehicles with the affected switch,” the company said in the letter.

Owners of the affected vehicles were urged not to park their cars in garages or near homes.

Models included in the latest action:

* 1995-2003 Ford Windstars.

* 2000-2003 Ford Excursion diesels.

* 1993-1997 and 1999-2003 Ford F-Super Duty diesels.

* 1992-2003 Ford Econolines.

* 1995-2002 Ford Explorers and Mercury Mountaineers.

* 1995-1997 and 2001-2003 Ford Rangers.

* 1994 Ford F53 motorhomes.