Over the years, Ford Expedition owners have reported a variety of problems with the defroster in this vehicle. Frequently the problems lead to a common cause, but troubleshooting is complicated. Ford owners should understand how the climate control system works before jumping to conclusions. When a problem is clearly identified, professional service on the vehicle is often necessary.
Many owners suspect defroster problems for operation that is actually running correctly. For example, the Expedition defrost mechanism often feeds air through part of the air conditioning system, yielding what appears to be cool AC. Users are occasionally confused as to the kind of air that should in fact be emitted from the defroster and assume this is a malfunction. However, the defrosting system makes adjustments based on a variety of criteria and can perform well without the same consistent behavior.
There are two legitimate primary problems associated with the defroster in Ford Expeditions, though a variety of other, less common issues have also been reported. The most prevalent condition relates to the wrong type of airflow emitting from the defroster, or the defroster vents improperly serving up air destined for other areas of the vehicle. Because of the way an Expedition works the defrost, a professional opinion is often necessary to discern if in fact there is a problem. Also common is rear defroster malfunction caused by circuit failure.
Owners report defroster-related problems on Ford Expeditions from any year. Models since the 1990s regularly appear in owner complaints regarding defrost problems, or related issues to defrost vents. While these various functional deficiencies affect the entire Expedition line, the 2005 models have the highest incidence of documented circuit failure. Ford has never issued a formal recall for a defrost problem, however, so exact numbers of affected vehicles are unknown.
A common source for defrost-related problems in the Ford Expedition is the vacuum line that leads to the defrost system. Leaks in this line and associated hoses can create a variety of problems. If airflow shifts between vents and the defroster during acceleration or other pressure placed on the engine, this is further evidence of damage in the vacuum system. The vacuum lines can be tested with a vacuum pump to verify any damage.
Any attempt to troubleshoot problems with the vacuum system should be handled by qualified service personnel only. The motors in Ford Expeditions, which regulate the defrosting mechanism, can be challenging to work with. While the cause for defroster problems may eventually prove to be a simple one, arriving at a proper diagnosis involves a detailed understanding of the blower motor engineering.
