97 Taurus defrost/heater issue

I have a 97 taurus that takes forever to defrost the windshield. There is alway a lot of moisture on the inside of the window, and it takes forever before the defroster blows barely warm air (it never gets really warm). I live in the northwest, but also don’t have this problem with any other car I’ve had here.

A couple of possibilities:

  1. Your a/c system isn’t functioning. The defroster uses the a/c to dehumidify the air.
  2. Your heater core is plugged up, the blend door in the HVAC isn’t working, your coolant level is low, or your thermostat is stuck open. Any of these will prevent the air from getting warm.

if it was just the AC, then the air coming out would be warm. So more likely is the heater core. Is the engine temperature normal?

It does not sound exactly right, but make sure you don’t have it set to re-circulate.

I would also suggest that unless you know the engine temperature is reaching normal, that it could be a defective radiator thermostat.

engine temp seems in the normal range, somewhere around 1/3 to 1/2 up the scale. ford made sure there is no option to change fresh or re-circ air. so when in defrost, it’s always fresh air, which stinks when behind a diesel.

I’ve bought a new thermostat to put in, will let you know if that does the trick (don’t have time to do it until the weekend).


while your at you should flush out the heater core, heres how.

  1. Remove heater hose where the two coolant sensors are by the thermostat housing.

  2. Remove the other heater hose line at the water pump, and direct it into a catch pan under the car.

  3. If there is a by pass rubber heater hose running across the fire wall you will need something to crimp it closed while flushing the heater core, Channel locks will work.

  4. Take a garden hose with the end cut off (old washing machine hose with the end cut off and screwed to the end of a water nozzle works well).
    Stick cut off hose into the heater line by the thermostat that was previously removed, and flush it out.

  5. Put back together, fill up with coolant, and enjoy the heat.

  6. There is alway the possibility the water pump is the cause of the problem. The Pump impeller can erode away if there was a lot of rust in the coolant.
    Good luck

You may have a heater core leak, in addition to the temperature problem. Not uncommon. A big job to replace heater core.