My air conditioner does not work on my 2005 f150. All the display lights turn on at the same time and none of the buttons will control air or heat. Please advise.

I would start with disconnecting the EATC / EMTC ( Electronic Automatic / Manual Temperature Control ) panel.

Open the ash tray, and pull each lower corner out, they are held on with spring clips. Working your way up the center trim panel, there are 6 ( 3 on each side- black circles in the picture above ).
When you get to the top, be cautious, the Passenger side airbag deactivation lamp has small wires on it, don't pull too hard ( green circle above )
On the back of the EATC / EMTC panel are 2 cam over connectors ( blue circles in the picture above ), release the cam tab, and they will disconnect.
When you reconnect it, it will default to off. Next is to run the self test calibration process ( pay attention to the temperature range ).

I have found some times the EATC / EMTC panel will just freeze up, and disconnecting it, and recalibrating it will make it work again. Few of them have not seen a problem again in 2+ years.
Electronic Automatic Temperature Control Module On-Demand Self-Test The EATC module on-demand self-test will retrieve on-demand (hard fault) DTCs only, it will not retrieve continuous DTCs. Continuous DTCs can be cleared when exiting the EATC module on-demand self-test. Make sure to retrieve continuous DTCs by carrying out the Electronic Automatic Temperature Control Module - Retrieve Continuous DTCs procedure before clearing any continuous DTCs.


•The EATC module on-demand self-test will not detect concerns associated with data link messages like engine coolant temperature or vehicle speed signals. A diagnostic tool must be used to retrieve these concerns.
•The EATC module on-demand self-test will detect concerns in the system control functions and will display on-demand (hard fault) DTCs for concerns that are present during the self-test. The vehicle interior temperature should be between 4°-38°C (40°-100°F) when performing the self-test. If the temperatures are not within the specified ranges, false DTCs may be displayed.
•The self-test can be initiated after cycling the ignition switch from OFF to ON. Normal operation of the climate control system stops when the self-test is activated.
•To enter the self-test, press the OFF and DEFROST buttons simultaneously and release, then press the AUTO button within 2 seconds . The display will show a flashing blower icon for 20 seconds , after which all vacuum fluorescent segments will be displayed if there are no on-demand DTCs present. If DTCs are present the EATC module will display "00 00" and then on-demand DTCs. Record all DTCs displayed.
•If any DTCs appear during the self-test, carry out the diagnostic procedure. Refer to the Electronic Automatic Temperature Control Module Diagnostic Trouble Code Index and follow the ACTION for each DTC given. See: Diagnostic Trouble Code Descriptions
•If a condition exists but no DTCs appear during the self-test, GO to Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Incorrect Operation. See: Symptom Related Diagnostic Procedures
•To exit the self-test and retain all DTCs, press any button except DEFROST. The EATC module will exit the self-test and retain all DTCs.
•To exit the self-test and clear all DTCs, press the DEFROST button. The EATC module will exit the self-test and all DTCs will be cleared.
•Always exit the self-test before powering the system down (system turned OFF). Once the self-test is exited, the ignition switch must remain ON for at least 30 seconds to allow the door actuators to automatically recalibrate.
•Continuous DTCs will be deleted after 80 ignition switch ON cycles after the intermittent fault occurs.

Electronic Automatic Temperature Control Module - Retrieve Continuous DTCs
The EATC module will retrieve only continuous (intermittent and hard) DTCs when carrying out this procedure.


•Retrieval of continuous DTCs can be initiated after cycling the ignition switch from OFF to ON. Normal operation of the climate control system stops when retrieving continuous DTCs.
•To retrieve continuous DTCs, press the OFF and DEFROST buttons simultaneously and release, then press the RECIRC button within 2 seconds . All vacuum fluorescent segments will be displayed if there are no continuous DTCs present. Continuous DTCs are indicated by the presence of the degrees Celsius symbol (°C) on the EATC module display. Record all DTCs displayed.
•If any DTCs appear, carry out the diagnostic procedure. Refer to the Electronic Automatic Temperature Control Module Diagnostic Trouble Code Index and follow the ACTION for each DTC given. See: Diagnostic Trouble Code Descriptions
•If a condition exists but no DTCs appear, GO to Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Incorrect Operation. See: Symptom Related Diagnostic Procedures
•To exit and retain all continuous DTCs, press any button except DEFROST. The EATC module will exit the retrieved continuous DTCs mode and retain all continuous DTCs.
•To exit and clear all continuous DTCs, press the DEFROST button. The EATC module will exit the retrieve continuous DTCs mode and all continuous DTCs will be cleared.
•Always exit the procedure before powering the system down (system turned OFF). Once the procedure is exited, the ignition switch must remain ON for at least 30 seconds to allow the door actuators to automatically recalibrate.
•Continuous DTCs will be deleted after 80 ignition switch ON cycles after the intermittent fault occurs.

Electronic Automatic Temperature Control (EATC) Module and Electronic Manual Temperature Control (EMTC) Module Cold Boot Process The purpose of the cold boot process is to allow the EATC or EMTC module to re-initialize and calibrate the door actuators. To carry out the cold boot process, follow the steps below.

1.Turn the ignition switch to the OFF position.
2.Disconnect the EATC or EMTC module electrical connectors.
3.Wait one minute .
4.Connect the EATC or EMTC module electrical connectors.
5.Turn the ignition switch to the ON position.
6.Select any position except OFF on the EATC or EMTC module. The EATC or EMTC module will now initialize and calibrate the mode doors. Calibration of the mode doors will take approximately 30 seconds .

There most likely is a problem with the ac system,and the system has shut down,if you ever have had the battery cables off,and you know it is ok to remove the negative battery cable for 20 seconds,then do this to reset the system,but if you are not sure ,do not,or you can loose all memory to the computer,and it will cause the dealer to have to reprogram the computer,now when,and if it resets,then the ac system will have to be checked to see why the ac system shut down,