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Questions and Answers

Mercury Mountaineer Blend Door

Q. Dear Mr. Ciulla, We have a 1997 Mercury Mountaineer. 120,000 miles, automatic transmission, 302 V-8 engine and A/C. The climate control does not work properly. It is a manual system versus an automatic system. The only way to get cold air is to have it on MAX A/C and otherwise, we are unable to adjust the temperature.

Mercury Mountaineer Blend Door

In researching the internet, I found some information pertaining to the Blend Door and how many Ford products have these break prematurely. The truck is out of warranty so I am looking for a way to confirm the problem then fix it myself if I can.

There are times when we hear a door move inside the heater plenum when we change the temperature selector position but most times nothing happens. Could the blend door be the problem? How do I isolate the problem? Is it possible for me to repair this myself?

The information I found on the internet says that to have a repair shop do this would cost $600.00 or $700.00 or more. Any tips or troubleshooting ideas along with possible ways for me to repair this myself would be greatly appreciated.

Most sincerely,

A. There is a TSB out on this problem.

Article No.: 98-23-20

Date: 11/23/98

1997- 1998 Crown Victoria, Taurus

1997 Town Car
1997-1998 Continental, Grand Marquis, Sable

Light Truck:
1997-1998 Explorer, Mountaineer

Some vehicles with a very low odometer reading may experience a lack of temperature control. This may be caused by the incorrect blend air door actuator being installed during the manufacturing process.

Install the correct blend air door actuator. Refer to the following text and Actuator Chart to determine if the correct blend air door actuator is installed on the vehicle.

Vehicles which are equipped with manual and Electronic Automatic Temperature Control (EATC) use different actuators. The actuators are marked "MAN" for manual and "EATC" or "ATC" for EATC systems. These markings are found on the part number sticker on the actuator.

1998 actuators differ from 1997 actuators on some vehicles (Crown Victoria/Grand Marquis, Continental, Explorer/Mountaineer) and are not interchangeable. Installation of the wrong actuator can cause potentiometer failure on manual systems, and no temperature control for both manual and EATC systems, as well as Diagnostic Trouble Code (DTC) 24 or 25 on EATC systems.

The proper actuator for your car is Engineering Number F77H-19E694-AA and Part Number F77Z-19E616-AA.

I would check this out before I go any further.

Additional Information provided courtesy of ALLDATA

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