Mechanics

I HAVE A GRAND . THE HEATER BLOWS COLD AIR. COOLANT LEVEL IS OK. I REPLACED THE THERMOSTAT, NO CHANGE. HELP !!

2006 Mercury Marquis • 26,000 miles

Also the door under the dash opens and closes turning heat on and off.
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Meswa
October 10, 2011.



The door you hear is the blend air door. It is what determines the temp that enters the vehicle. Check the actuator on the door. If it is moving around, you will get heat and then outside air (cool).


I watched the door open and close.
I still don't get heat, only cold air?


Tiny
Meswa
Oct 10, 2011.
Okay, I need you to check something. I thought the door was working on and off. With the engine hot, the heater on high, feel both heater core hoses at the fire wall. Are both hot?


Yes


Tiny
Meswa
Oct 10, 2011.
If the hoses are both hot, then something has to be heppening with the blend door not staying positioned correctly.


Is there more than one door?
The one inside that is in front of the blower motor opens and closes switching from air to heat.


Tiny
Meswa
Oct 10, 2011.
No, that is it. I tried to find a picture. The best I could find was of the actuator. Take a look and let me know if it looks the same as what you are seeing.


No. The door is vertical. Opens with Air cond and closes when I move the switch to heat.
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Tiny
Meswa
Oct 10, 2011.

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