Troubleshooting Hints - Temperature Controls

TROUBLESHOOTING HINTS

1. If the Air Mix Door is disturbed for any reason, you must disconnect the Battery or the Heater and A/C Programmer momentarily to start the calibration sequence. During the calibration process the Blower Motor will not operate for approximately 14 minutes.
2. After an Outside Temperature Sensor has been changed or is open, the external temperature will read -50°F and Code O3 will be set until the vehicle has been driven over 25 mph for three minutes.
3. The Outside Air Temperature Display will not increase until vehicle is driven over 25 mph for three minutes.
4. If a low freon fault Code O9 is set, the A/C Compressor will not operate. To reset this code, disconnect Battery or pull the CTSY Fuse, then reconnect.

SYSTEM DIAGNOSIS

Diagnosis for this system is based on diagnostic codes stored in the Heater and A/C Control Head. When a code has been stored the MODE Indicator (LED) of the current mode will flash. Three dashes will be displayed on the Heater and A/C Control Head if the A/C Programmer fails. For code diagnostics, refer to A/C and Heating System.
If Heater and A/C Control Head and/or Programmer appear completely inoperative, refer to "Electronic A/C: System Check".