Two problems related to defogger controls have been reported for the 1998 Mercury Mystique. The most recently reported issues are listed below.
There is a short in the abs controller system which causes the fuse for the fan blower to blow therefore there is no heat and no abs which makes the car inoperable. When I took my car into the Ford dealer there was another lady with the same problem.
Blower resistor and motor burned out due to faulty plugs. The dealer has inspected and repaired the vehicle.