A/C - Temperature Control Inoperative

Article No.
97-24-25

11/24/97

AIR CONDITIONING - DISCHARGE AIR
TEMPERATURE DOES NOT CHANGE WHEN MOVING
TEMPERATURE LEVER

LIGHT TRUCK:
1995-97 EXPLORER
1997 MOUNTAINEER

ISSUE:
The discharge air temperature from the A/C-Heater system may not change when the temperature lever is moved. This may be caused by a broken blend air door.

ACTION:
Install a new plenum which has a revised blend air door and should reduce the possibility of cracking. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

1. Stabilize the vehicle at room temperature (between 40 and 38°C (40° and 100°F).

2. Enter Electronic Automatic Temperature Control (EATC) module self test mode by simultaneously pressing the "OFF" and "FLOOR" buttons and releasing, then pressing the "AUTO" button within 2 seconds. Immediately press the "DEFROST" button to exit and clear any codes that may have been accidentally set.





3. Re-enter the self test mode. The control will display a series of segments for 20 seconds after which all vacuum fluorescent display segments will be displayed if no faults are found. If a fault is found, a DTC will be displayed as shown in the Diagnostic Trouble Code (DTC) Chart. Refer to the appropriate Service Manual for proper diagnostics.

4. If no codes are present, press the "PANEL-FLOOR" button and set the temperature set point to 32°C (90°F), rotate the blower motor thumbwheel fully up and measure the discharge air temperature.

^ If the air discharge temperature is cool at the 3200 (90°F) set point temperature, then the blend air door is most likely broken. Remove the blend door actuator and inspect the blend door for cracks where the actuator rod fits into the door. If the blend door is broken, replace the plenum assembly as outlined in the appropriate Service Manual

^ If the discharge air temperature is warm or hot at the 3200 (90°F) set point temperature, then set the temperature set point to 16°C (60°F) and measure the discharge air temperature

^ If the discharge air temperature at a 16° (60°F) set point temperature is warm or hot, perform the refrigerant tests outlined in the appropriate Service Manual

PART NUMBER PART NAME

F77Z-18471-HA Plenum Assembly

OTHER APPLICABLE ARTICLES: NONE

WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME

972425A Replace Plenum Assembly 4.2 Hrs.
(Includes Instrument Panel
Removal And Installation)

DEALER CODING
CONDITION
BASIC PART NO. CODE
18B545 01

OASIS CODES: 208000, 208200, 208300, 208999