The National Highway Traffic Safety Administration Thursday urged owners of certain unrepaired Ford, Lincoln and Mercury SUVs, pickup trucks, vans, and certain passenger cars to bring their vehicles to dealer repair shops immediately.

The NHTSA said the vehicles need to have the the cruise control switch disconnected. Failure to have the switch disconnected could lead to a vehicle fire at any time, whether or not the key is in the ignition, and whether or not owners use the cruise control system.

Many dealers will perform this as a "drive-through" service so owners do not have to leave their vehicles at the dealership or schedule an appointment in advance.

The safety agency said the fire danger is present regardless of the age of the vehicle, and could occur while the vehicle is parked and unattended. Several dwelling fires have been attributed to the problem.

NHTSA said it is issuing the consumer advisory due to concerns that many owners have yet to respond to multiple safety defect recall notifications involving approximately 9.6 million registered vehicles.

It said that approximately 5 million vehicles have been repaired so far, leaving about 4.6 million passenger cars and light trucks with the faulty switches intact, and in danger of catching fire.

Ford and NHTSA urged all owners of recalled vehicles that have not been repaired to bring their vehicles to dealers as soon as possible to have the faulty switches disconnected, as an interim safety measure. Ford is in the process of re-notifying owners of the SUVs and other light trucks concerning the importance of having the switch disconnected.

This interim fix will eliminate the risk of fire while affected Ford and Mercury owners are waiting for final repairs from the company, NHTSA said.

The involved vehicles are:

• 1993-2004 F150
• 1993-1999 F250 (gasoline engine)
• 1993-1996 Bronco
• 1994-1996 Econoline
• 1997-2002 Ford Expedition
• 1998-2002 Lincoln Navigator
• 1998-2002 Ford Ranger
• 1992-1998 Ford Crown Victoria, Mercury Grand Marquis and Lincoln Town Car
• 1993-1998 Lincoln Mark VIII
• 1993-1995 Ford Taurus SHO with automatic transmission
• 1994-Mercury Capri
• 1998-2001 Ford Explorer and Mercury Mountaineer
• 2001-2002 Ford Explorer Sport and Explorer Sport Trac
• 1992-1993 and 1997-2003 Ford E-150-350 gasoline or natural gas vehicles
• 2002-E-550 gasoline engine vehicles
• 1996-2003 E-450 gasoline or natural gas vehicles
• 1994-2002 F-250 through F-550 super Duty trucks (gasoline engine)
• 2000-2002 Ford Excursion (gasoline engine)
• 2003-F250-F550 Super Duty, Ford Excursion
• 1995-2002 Ford F53 Motor home chassis
• 2002-2003 Lincoln Blackwood

Ford is also recalling 470,000 2005-2008 Mustangs to recalibrate the strength of the cars' front passenger airbag deployment. Company officials said that Mustang owners will get letters starting Saturday.