One problem related to defogger heater has been reported for the 2003 Mercury Sable. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Mercury Sable based on all problems reported for the 2003 Sable.
Ford taurus and the Mercury Sable's have a problem with water leaking into the heater core box which eventually causes the heater motor and stop working. I understand from reading post on the internet that is apparently a design flaw. My car had 44,000 miles at the point where the motor quit working. The bill to repair the car was $471. 28. The warranty had obviously expired but I felt like Ford motor CO should re-imburse the cost of the repair since it is a very common problem. They declined to help with the cost of the repair.