Mercury Mystique Defroster

1998 Mercury Mystique Stuck In Default Defrost, How Can I Repair This Problem (is There A Video & Written Instructions On How To Fix This...

98 Mystique Blows Cool & Hot Air Out Defrost Vent Only, Is There A Check Valve Or Something And Where Is It Located, How Do I Check My...

This Past Winter My Car Started Having Strange Symptoms, Whenever It Would Get Cold, Like 30 Degrees, And I Would Have My Heater Or Defrost...