Having problems with your 2003 Mercury Mountaineer ?
Cold air blows out of the defrost. does the thermostat need to replaced?
Thermostat wouldn't likly cause that. You've probably got a problem with the system that controls the flap doors in the duct system for heat and AC. The flap door may be stuck in the AC position. If you have no heat in the rest of the vehicle either, the switch between heat and AC may be the problem.
Repair Help & Product Troubleshooting for 2003 Mercury Mountaineer
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