The blend door that controls the heat and air conditioning has stopped working and has rendered my heating / cooling system dysfunctional. This seems to be a widely known issue for this car (1998 Lincoln Mark viii lsc) - it poses a dangerous and tangible threat to safety considering heat will not work to defrost the windows and front windshield.

- Arlington Heights, IL, USA

Heater/ac blender door-doors, fail to operate and or have "no" tempeture control, resulting in poor visiblity.fogging etc, lack of defrosting and or a cold driver..see previous 768368,768427,768529,768796,768173.7689173,769183,769959,10003517,10005626,10023956,10075009, and now mine ! the only thing that changed is the cost of repairs by the dealer has gone up. I have a written estimate for( the dash has to be removed) $680 labor.. parts as found/ to be $38, ,$68, ,$5, ,$35 and than maybe $350 more for a plemum.. ($1,176) I understand that Ford has replaced the parts with better versions as to materials that with stand the different temperatures it is subject too.this apparent lack of action by NHTSA is cause for concern as to your uninterest in the public safety not knowing how many other vehicles are out their with this hazardous defect. Help us, protect us, ,thank you.

- Redding, CT, USA

I have been reviewing the file on Lincoln mark 8's '97 & 98 and noticed that there were at least 10 complaints about the ventilation/heating/A/C blend door problem with this car. How many complaints does it take until you do something about it"??? this is not only a very expensive repair to make, but failure, which can happen without warning, results in windshield fogging and inability of the system to clear the windshield. The Lincoln of distinction club, which supports mark 8's have had over 30-40 failures to date, some repeatedly. We now found that this failure happens in Lincoln town car/ taraus, etc, and that Ford has recently changed the replacement part designation. This strikes us as an acknowledgement that they are aware of the problem, but don't want to belly up to the bar and admit it. Can't your offices do anything or is this just a waste of our time trying to get a government Agency to move on something that they claim they want to assist but ends in frustation of the citizens who take your charter seriously".

- Silver Spring, MD, USA

Blend door actuator is broken. This causes a serious visibility hazard do to fog on the windows that could lead to personal injury.

- Fairfax, VA, USA

Blend door no heat or defrost only cold air.

- Calhoun City, MS, USA

While driving down the road, because of the weather conditions, I noticed that the windshield was getting clouded over. Turned on my ha/C to defog the windshield but only cold air came out adding greatly to the windshield fogging. I was able to stop the car before running into opposite lanes of traffic since I couldn't see out the windshield. I got a cloth and wiped it clear to procede. Took to local dealer and was told that it was a common problem to these cars aswell as town cars in that the blend door actuator causes the door's arm to break in a set position. Thus if broke on hot setting you get only heated air- vice versa on a cold setting. It was an apparently poorly designed plastic item; however the charge to fix it with another similar arm would be over $500 because they have to take the dash off the car make the repair, though the part is lss than $35. I could not afford the repair at that time, so a technician showed me how to lay under the dash and manually pull the door to either hot or cold.

- Silver Spring, MD, USA

The blend door actuator arm is a common failure on these cars. Due to their poor craftsmanship, they are almost guaranteed to fail eventually. Having no heat in the winter can be a serious safety issue. Not being able to defrost windows is the most obvious safety concern. This defect should be on a national recall.

- Roosemount, MN, USA

Air blend door malfunctions causing no heat to blow on windshield in cold weather will cause fogged up windshield also. Both conditions cause poor visibility.

- Newark, OH, USA

Rainy day/moist conditions/heat temp. Uncontrollable causing immediate strong "fog-up" of windshield at highway speed.

- Westfield, MA, USA

Actuator fails, thus never allowing temperature to change in car. Windshield fogs up causing a safety hazard.

- Platte City, MO, USA

The part failure is a cracked plastic arm actuator attached to the motor that controls the flow of air to the windshield defroster. When the part cracked, the blend door motor is not able to direct air to the windshield defroster. I had the part replaced by a local Lincoln dealer (they had to remove the entire dash board to replace the blend door motor and arm - not sold separatly) this year. It is a very dangerous defect, and it occurs without warning.

- Kennesaw, GA, USA

The on-board computer indicates that the "drivers door is ajar". the sign does not go out when the door is opened and closed again. When door locks are depressed, they pop up again and the doors will not lock at all. The only operable setting of the heater blower motor is high fan/ the headlight assembly ballast is defective and the lowbeam setting is dim. It cannot be repaired by replacing the lamp.

- Washington, DC, USA