A/c-Heater System - Automatic: Other Lincoln Mark I

SERVICING PRECAUTIONS

DISABLING SYSTEM

1. Disconnect negative battery cable. Disconnect battery backup power supply, located behind right side of instrument panel, above glove box.
2. Remove nuts and washers holding air bag module to steering wheel. Disconnect air bag module connector. Jumper Gray/Orange wire to Pink wire of air bag connector. Reconnect negative battery cable and backup power supply.

AIR BAG SYSTEM FUNCTIONAL CHECK

Air bag system is normal if AIR BAG light illuminates for approximately 6 seconds when ignition key is turned to ON position. Air bag system needs service if AIR BAG light does not light, stays lit, flashes or if groups of 5 beeping tones are heard.

ERROR CODE 01 (BLEND DOOR ACTUATOR)

1. Check error codes recorded during self-test. If error code 05 appears along with Code 01, go to next step. If not, go to step 7).
2. Unplug ATC control panel passenger's side connector. Turn ignition off. Place ignition switch in RUN position and re-enter self-test. If Code 05 is not displayed, go to step 4). If Code 05 is still displayed, go to next step.
3. Replace ATC control panel and retest system using self-test. If blend door actuator works okay, end test. If blend door actuator is still inoperative, go back to step 1).
4. Reconnect ATC control panel connector and disconnect wiring harness from actuator. Turn ignition off. Place ignition switch in RUN position and re-enter self-test. If Code 05 is still displayed, go to next step. If Code 05 is not displayed, go to step 6).
5. Repair wiring harness. After repairs, connect wiring harness and retest system using self-test. If blend door actuator works okay, end test. If blend door actuator is still inoperative, go back to step 1).
6. Replace blend door actuator and retest system using self-test. If blend door actuator works okay, end test. If blend door actuator is still inoperative, go back to step 1).
7. Unplug both connectors at ATC control panel. Place ignition switch in RUN position. Connect jumper wire across ATC control panel connector pin numbers. See BLEND DOOR ACTUATOR TEST table.
8. If actuator does not operate in both directions, go to step 9). If actuator operates in both directions, plug in ATC control panel connectors and retest system using self-test. If blend door actuator works okay, end test. If not, go to step 10).
9. Check wiring harness and connectors for damage. Unplug connectors and check temperature blend door actuator wiring for continuity. see scheme 3 See WIRING DIAGRAM at end of article. If okay, plug connectors back in and go back to step 6). If not, go back to step 5).
10. Using an ohmmeter, check resistance between pins No. 4 and No. 5 at ATC control panel passenger's side connector. See WIRING DIAGRAM at end of article. Reading should be 500-600 ohms. Check resistance between pins No. 4 and No. 2. Reading should be 40-550 ohms.
11. Also check resistance between pins No. 5 and No. 2. Reading should be 200-600 ohms. If all readings are correct, go back to step 3). If all readings are incorrect, go back to step 9).

Note. Perform actuator tests carefully. Incorrect pin combinations may damage ATC system components.

ERROR CODE 02 (FLOOR/PANEL DOOR ACTUATOR)

1. Check error codes recorded during self-test. If Code 06 appears along with Code 02, go to next step. If Code 06 does not appear, go to step 7).
2. Unplug ATC control panel passenger's side connector. Turn ignition off. Place ignition switch in RUN position and re-enter self-test. If Code 06 is not displayed, go to step 4). If Code 06 is still displayed, go to next step.
3. Replace ATC control panel and retest system using self-test. If floor/panel door actuator works okay, end test. If floor/panel actuator is still inoperative, go back to step 1).
4. Reconnect control panel and disconnect wiring harness from actuator. Turn ignition off. Place ignition switch in RUN position and re-enter self-test. If Code 06 is still displayed, go to next step. If Code 06 is not displayed, go to step 6).
5. Repair wiring harness. After repairs, connect wiring harness and retest system using self-test. If floor/panel door actuator works okay, end test. If actuator is still inoperative, go back to step 1).
6. Replace floor/panel door actuator and retest system using self-test. If floor/panel door actuator works okay, end test. If actuator is still inoperative, go back to step 1).
7. Unplug both connectors at control panel. Place ignition switch in RUN position. Connect a jumper wire across control panel connector pin numbers. See FLOOR/PANEL DOOR ACTUATOR TEST table.
8. If actuator does not operate in both directions, go to next step. If actuator operates in both directions, plug in control panel connectors and retest system using self-test. If floor/panel door actuator works okay, end test. If not, go to step 10).
9. Check wiring harness and connectors for damage. Unplug connectors and check floor/panel actuator wiring for continuity. see scheme 3 See WIRING DIAGRAM at end of article. If okay, plug connectors back in and go back to step 6). If not, go back to step 5).
10. Using an ohmmeter, check resistance between pins No. 4 and No. 5 at control panel passenger's side connector. See WIRING DIAGRAM at end of article. Reading should be 500-600 ohms. Check resistance between pins No. 13 and No. 4. Reading should be 75-550 ohms.
11. Also check resistance between pins No. 13 and No. 5. Reading should be 200-600 ohms. If all readings are correct, go back to step 3). If all readings are incorrect, go back to step 9).

ERROR CODE 03 (PANEL/DEFROST DOOR ACTUATOR)

1. Check error codes recorded during self-test. If Code 07 is also displayed, go to next step. If Code 03 is displayed (no Code 07) and door is inoperative, go to step 7). If Code 03 is displayed (no Code 07) and door drives continuously, go to step 9).
2. Remove pin No. 9 from ATC control panel passenger's side connector (leave connector on). See WIRING DIAGRAM at end of article. Turn ignition off. Place ignition switch in RUN position and re-enter self-test. If Code 07 is not displayed, go to step 4). If Code 07 is still displayed, go to next step.
3. Replace ATC control panel and retest system using self-test. If panel/defrost door actuator works okay, end test. If panel/defrost door actuator is still inoperative, go back to step 1).
4. Reconnect ATC control panel and disconnect wiring harness from actuator. Turn ignition off. Place ignition switch in RUN position and re-enter self-test. If Code 07 is still displayed, go to next step. If Code 07 is not displayed, go to step 6).
5. Repair wiring harness. After repairs, connect wiring harness and retest system using self-test. If panel/defrost door actuator works okay, end test. If actuator is still inoperative, go back to step 1).
6. Replace panel/defrost door actuator and retest system using self-test. If panel/defrost door actuator works okay, end test. If actuator is still inoperative, go back to step 1).
7. With system in automatic mode, set ATC control panel to HI blower speed. Unplug control panel driver's side connector. Blower motor should work. Connect a jumper wire across connector pins No. 8 and No. 9, and then between pins No. 4 and No. 10. If actuator moves in both directions (10 seconds or less), go to next step. If movement is restricted, go to step 10).
8. Plug in control panel connector and retest system using self-test. If panel/defrost door actuator works okay, end test. If panel/defrost door actuator is still inoperative, go back to step 3).
9. Check continuity of Orange/Black wire (circuit No. 776) from panel/defrost door actuator to pin No. 3 at control panel driver's side connector. See WIRING DIAGRAM at end of article. If wire is okay, go to step 13). If not, repair wiring and retest system using self-test.
10. Ensure actuator is not tangled in wiring harness (external obstruction) or internally restricted. If an external obstruction, clear and retest system using self-test. If internal, replace actuator and retest system using self-test.
11. Check continuity between pins No. 9 and No. 10 at ATC control panel driver's side connector. If circuit is open, go to next step. If resistance reading is less than 100 ohms, go back to step 6).
12. Ensure panel/defrost door actuator connector is properly plugged in. If okay, go back to step 6). If connector is not proper, connect actuator properly and retest system using self-test.
13. Replace actuator and retest system using self-test. If panel defrost door actuator works okay, end test. If actuator is still inoperative, go back to step 3).

ERROR CODE 04 (FRESH/RECIRCULATED AIR DOOR ACTUATOR)

1. Check error codes recorded during self-test. If Code 08 is also displayed, go to next step. If Code 04 is displayed (no Code 08) and door is inoperative, go to step 7). If Code 04 is displayed (no Code 08) and door drives continuously, go to step 10).
2. Unplug ATC control panel passenger's side connector. Turn ignition off. Place ignition switch in RUN position and re-enter self-test. If Code 08 is not displayed, go to step 4). If Code 08 is still displayed, go to next step.
3. Replace ATC control panel and retest system using self-test. If fresh/recirculated air door actuator works okay, end test. If fresh/recirculated air door actuator is still inoperative, go back to step 1).
4. Reconnect ATC control panel and disconnect wiring harness from actuator. Turn ignition off. Place ignition switch in RUN position and re-enter self-test. If Code 08 is still displayed, go to next step. If Code 08 is not displayed, go to step 6).
5. Repair wiring harness. After repairs, connect wiring harness and retest system using self-test. If fresh/recirculated air door actuator operates properly, end test. If actuator is still inoperative, go back to step 1).
6. Replace fresh/recirculated air door actuator and retest system using self-test. If fresh/recirculated air door actuator works okay, end test. If actuator is still inoperative, go back to step 1).
7. Unplug both connectors at ATC control panel. Place ignition switch in RUN position. Connect a jumper wire across ATC control panel connector pin numbers indicated in FRESH/RECIRCULATED AIR DOOR ACTUATOR TEST table. See WIRING DIAGRAM at end of article.
8. If actuator moves in both directions (10 seconds or less), go to next step. If actuator movement is restricted in both directions (longer than 10 seconds), go to step 10). If actuator does not move at all, go to step 11).
9. Plug in ATC control panel connector and retest system using self-test. If fresh/recirculated air door actuator works okay, end test. If actuator is still inoperative, go back to step 3).
10. Check continuity of Yellow/Lt. Blue wire (circuit No. 248) from fresh/recirculated air door actuator to pin No. 12 of ATC control panel passenger's side connector. If wire is okay, go to step 6). If not, repair wiring and retest system using self-test.
11. Ensure actuator is not tangled in wiring harness (external obstruction) or internally restricted. If obstruction is external, clear and retest system using self-test. If internal, replace actuator and retest system using self-test.
12. Check continuity between pins No. 1 and No. 3 at ATC control panel passenger's side connector. If circuit is open, go to next step. If resistance reading is less than 100 ohms, go back to step 6).
13. Ensure fresh/recirculated air door actuator connector is properly plugged in. If okay, go back to step 6). If not, connect actuator properly and retest system using self-test.
14. Replace actuator and retest system using self-test. If fresh/recirculated air door actuator works okay, end test. If actuator is still inoperative, go back to step 3).

ERROR CODE 05 (BLEND DOOR ACTUATOR CURRENT)

See ATC SELF-TEST - ERROR CODE 01.

ERROR CODE 06 (FLOOR/PANEL ACTUATOR CURRENT)

See ATC SELF-TEST - ERROR CODE 02.

ERROR CODE 07

1. When in combination with Code 03, see ATC SELF-TEST ERROR CODE 03 (Panel/Defrost Actuator Current). When displayed alone, Code 07 indicates compressor clutch always ON or always OFF failure. Follow steps 2) to 4).
2. Set ATC control panel in AUTO mode. Using DVOM, check voltage at Pin No. 2 (Gray/White wire) of Blower Motor Speed Controller (BSC) connector. If less than 5 volts, check for wiring shorts. If wiring okay, replace BSC. If more than 7 volts, replace BSC.
3. If clutch is not ON and reading in step 2) is 5-7 volts, check voltage at BSC connector Pin No. 6 (Lt. Green/Purple wire). See WIRING DIAGRAM at end of article. If reading is zero, replace BSC. If reading equals battery voltage, replace wiring harness and A/C pressure switch.
4. Set control in FLOOR mode and check voltage at Pin No. 2 (Gray/White wire) of BSC. If 7 volts or less, replace ATC control panel. If more than 7 volts and clutch is ON, replace BSC. If more than 7 volts and clutch is OFF, system okay.

ERROR CODE 08

When in combination with Code 04 (Outside/Recirculation Air Actuator Current), see ATC SELF-TEST - ERROR CODE 04. When displayed alone, Code 08 indicates compressor clutch always ON or always OFF failure. Follow steps 1) to 3) of Code 07 procedures .

ERROR CODE 09 (CLUTCH SIGNAL OUT OF RANGE)

Replace ATC control panel.

ERROR CODES 10 & 11 (AMBIENT TEMP SENSOR OPEN/SHORTED)

1. Disconnect ATC control panel connectors. Using ohmmeter, check resistance between Pin No. 10 (Pink/Black wire) and Pin No. 14 (Red/Orange wire) of passenger side connector. See WIRING DIAGRAM at end of article.
2. If resistance is not to specification, check for wiring shorts or opens. see scheme 4 If wiring okay, replace ambient temperature sensor. If resistance is okay, check in-vehicle temperature sensor. See ERROR CODES 12 & 13.

ERROR CODES 12 & 13 (IN-VEHICLE TEMP SENSOR OPEN/SHORTED)

1. Disconnect ATC control panel connectors. Using ohmmeter, check resistance between pin No. 2 (White/Orange wire) and pin No. 7 (Lt. Blue/Orange wire) of driver's side connector. See WIRING DIAGRAM at end of article.
2. If resistance is not to specification, check for wiring shorts or opens. (Scheme 8) If wiring okay, replace in-vehicle temperature sensor. If resistance is okay, replace ATC control panel.

Scheme 8

ERROR CODE 14 (ATC CONTROL PANEL PROBLEM)

If Code 14 appears, replace control panel.

ERROR CODE 15 (BLOWER MOTOR INOPERATIVE)

If Code 15 appears, set ATC control panel to HI blower speed in automatic mode. Measure voltage between pin No. 1 (Tan/Orange wire) of blower motor speed controller and pin No. 5 at ATC control panel driver's side connector. See WIRING DIAGRAM at end of article. If reading is greater than 10 volts, replace ATC control panel. If reading is 10 volts or less, replace blower motor speed controller.

ERROR CODE 88 (NO FAULTS FOUND)

No faults found during self-test. See SELF-TEST INDICATES NO ERRORS FOUND test.

COOL AIR DISCHARGE WHEN SET TO 90°F IN AUTO MODE

Check heater system for possible malfunction. Check blend door shaft attachment, door position, and blend door actuator. Blend door may not be in maximum heating position. If necessary, assume Code 01 was displayed. See ATC SELF-TEST - ERROR CODE 01.

WARM AIR DISCHARGE WHEN SET TO 60°F IN AUTO MODE

1. Check refrigerant level and A/C compressor clutch engagement. See NO A/C COMPRESSOR CLUTCH OPERATION test. Check blend door actuator shaft attachment, door position, and blend door actuator.
2. Blend door may not be in maximum cooling position. If necessary, assume Code 01 was displayed. See ATC SELF-TEST - ERROR CODE 01. Fresh/recirculated air door not in recirculation position. Assume Code 04 was displayed. See ATC SELF-TEST - ERROR CODE 04.

AIR IS DISCHARGED FROM WRONG AIR REGISTERS

Floor/panel door actuator out of position. Check door shaft attachment, door position, and floor/panel door actuator. If necessary, assume Code 02 was displayed. See ATC SELF-TEST - ERROR CODE 02.

NO BLOWER

Faulty cold engine lock-out switch. See BLOWER MOTOR SPEED CONTROLLER DIAGNOSIS - NO BLOWER test. Check wiring, blower motor, or blower motor speed controller for possible malfunction.

BLOWER OPERATES IN HIGH SPEED ONLY

See BLOWER MOTOR SPEED CONTROLLER DIAGNOSIS - BLOWER OPERATES IN HIGH SPEED ONLY test. Check wiring, ATC control panel, or blower motor speed controller for possible malfunction.

NO LO SPEED. OPERATES IN LOW SPEED WHEN SETTING CHANGES FROM 60°F to 90°F

Defective ATC control panel. See R & I procedures in this

article.

NO HI SPEED. OPERATES IN HIGH SPEED WHEN SETTING CHANGES FROM 60°F to 90°F

Defective ATC control panel. See R & I procedures in this

article.

BLOWER SPEED FIXED BETWEEN OFF & HI

Malfunctioning blower motor speed controller. See BLOWER MOTOR SPEED CONTROLLER DIAGNOSIS - FIXED BLOWER SPEED test. Defective ATC control panel. See R & I procedures in this article.

A/C COMPRESSOR CLUTCH IS ON WHEN IN OFF POSITION

See the A/C COMPRESSOR CLUTCH DOES NOT DISENGAGE WHEN IN OFF POSITION test. Defective blower motor speed controller. See R & I procedures in this article.

ATC CONTROL PANEL DIGITS & LEDS DO NOT LIGHT. BLOWER OFF

Check fuses. Ignition circuit to ATC control panel open.

ONE LED ON ATC CONTROL PANEL DOES NOT LIGHT

Defective control panel. See R & I procedures in this article.

COLD AIR IS DELIVERED DURING HEATING WHEN ENGINE IS COLD

1. Check cold engine lock-out (engine coolant temperature) switch for damage. Replace if necessary. If okay, press OFF/AUTO button and set temperature display to 90°F. see scheme 2
2. Turn ignition off. Ground Yellow/White wire at cold engine lock-out switch. If blower motor is off, replace cold engine lock-out switch. If blower motor is on, check wiring. If okay, replace ATC control panel.

SET TEMP DOES NOT RETURN TO SET POSITION AFTER IGNITION OFF

Check power fuse/wiring. Defective ATC control panel. See R & I procedures in this article.

TEMP DISPLAY WILL NOT SWITCH FROM FAHRENHEIT TO CELSIUS

Connect pin No. 14 of ATC control panel driver's side connector to ground. See WIRING DIAGRAM at end of article. Turn ignition on. If display does not switch from Fahrenheit to Celsius, Red wire (circuit No. 506) is shorted at ATC control panel or ATC control panel is defective.

SYSTEM DOES NOT CONTROL TEMPERATURE

In-vehicle temperature sensor hose disconnected or damaged, sensor seals missing or improperly installed, aspirator not secured to evaporator case. Repair or replace as necessary.

FRESH/RECIRC AIR OR PANEL/DEFROST DOORS RUN CONTINUOUSLY

Feedback circuit(s) open. Check connectors, wiring harness, or actuator(s).

1. With system in automatic mode, set temperature display to 60°F with engine running. If blower motor operates in high speed, go to next step. If blower motor does not work, go to step 4).
2. With system in automatic mode, set temperature display to 90°F with a warm running engine. Disconnect cold engine lock-out (engine coolant temperature) switch. If blower motor operates in high speed, replace cold engine lock-out switch. If blower motor does not operate in high speed, go to next step.
3. With cold engine lock-out switch disconnected, unplug ATC control panel driver's side connector. See WIRING DIAGRAM at end of article. Measure resistance between pin No. 6 on ATC control panel connector and ground. If open, replace ATC control panel. If shorted, repair wiring harness.
4. Check fuse. Replace if necessary. Test blower motor once again. If blower works okay, end test. If not, connect Orange/Red wire at blower motor connector to ground. If blower motor operates in high speed, go to next step. If not, check battery circuit to blower motor or replace blower motor.
5. Connect Tan/Orange wire (circuit No. 184) at blower motor speed controller to ground. If blower motor operates in high speed, go to next step. If not, replace blower motor speed controller.
6. Connect pin No. 5 of ATC control panel driver's side connector to ground. If blower motor operates in high speed, replace ATC control panel. If not, repair wiring harness.

Unplug ATC control panel driver's side connector. Install jumper wire between pins No. 5 and No. 8. See WIRING DIAGRAM at end of article. If blower motor stops, replace ATC control panel. If blower motor still runs at high speed, replace blower motor speed controller.

FIXED BLOWER SPEED

Unplug ATC control panel driver's side connector. Install jumper wire between pins No. 4 and No. 5. See WIRING DIAGRAM at end of article. If blower motor operates on high speed, replace ATC control panel. If blower motor speed stays the same, replace blower motor speed controller.

A/C COMPRESSOR CLUTCH ENGAGED IN OFF POSITION

Unplug ATC control panel driver's side connector. If A/C compressor clutch disengages, replace ATC control panel. If A/C compressor clutch remains engaged, replace blower motor speed controller.