Ford Motor Co. said Tuesday it will add 4.5 million older-model vehicles to the long list of those recalled because a defective cruise control switch could cause a fire.

The latest voluntary action pushes Ford's total recall due to faulty switches to 14.3 million registered vehicles over 10 years, capping the company's largest cumulative recall in history involving a single problem.

The recall covers 1.1 million Ford Windstar minivans that had a small risk of fire due to internal leaking from the switches. Ford said in a letter to federal regulators that it found a small number of reported fires linked to the problem during an internal investigation that began last year, but did not specify how many.

The remaining 3.4 million vehicles are Ford, Lincoln and Mercury models. Ford said there were no reports of fires with those models, most of them trucks and sport utility vehicles, but that they were included in the recall because they use the same switches. All vehicles covered by the recall are from the 1992 to 2003 model years.

Ford advised owners of all vehicles covered by the recall to park them outside until they are mailed instructions by the end of the month on how to get repairs.

The Dearborn, Mich.-based automaker has struggled for a decade with the problem, which has prompted hundreds of complaints and dozens of lawsuits over fires allegedly caused by faulty switches. A small number of injuries have also been linked to the problem, though none were reported in the latest recall. Previous recalls included some of Ford's most popular brands, like the popular F-series of pickup trucks.

Ford began an investigation of Windstar vehicles in February 2008 after receiving a growing number of reports of fires under the vehicles' hoods, according to a letter the company sent to the National Highway Transportation Safety Agency late last week announcing the recall. In June 2008, NHTSA began its own probe of the problem.

Investigators found that the switches, made by Texas Instruments, could leak internally, overheat and potentially ignite. NHTSA also identified four reports of leaking fluid damaging the antilock brake control module, resulting in a fire. The module is charged with electrical current and can ignite the fluid in rare cases, said Ford spokesman Wes Sherwood.

Even some vehicles without cruise control are part of the recall because they still have the switches with brake fluid routed through them. To repair the problem, dealers will install a harness to help prevent the fluid from flowing anywhere it could be ignited.

Ford stopped using the Texas Instruments switch in 2003, according to Sherwood. The latest group of vehicles recalled is the last batch still on the road that had the switch installed.

Texas Instruments said in a statement that it manufactured a switch "to meet and exceed Ford's specifications" and that it is only one component of Ford's cruise control deactivation system. The company cited a 2006 NHTSA investigation that found multiple factors were to blame for fires. Texas Instruments no longer owns the division that made the switches.

NHTSA spokesman Rae Tyson said Ford "is to be commended for stepping forward to resolve this issue."

The recall covers the following model years: 1995-2003 Ford Windstar; 2000-2003 Ford Excursion diesel; 1993-1997 and 1999-2003 Ford F-Super Duty diesel; 1992-2003 Ford Econoline; 1995-2002 Ford Explorer; 1995-2002 Mercury Mountaineer; 1995-1997 and 2001-2003 Ford Ranger; and 1994 Ford F35 Motorhome vehicles.