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Shawn
Shawn, Auto Service Technician
Category: Ford
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Experience:  16 years experience Ford,Nissan and Honda dealership in all areas
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99 ford expedition: Heater core is getting hot blender door is working

Resolved Question:

ok 99 ford expedition no heat. Put new thermostat in and new heater core. Heater core is getting hot blender door is working. Feels like cold air when I crank up to 90 degrees. The air conditioner was running so I unplugged the electric to air compressor helped a little bit but when you drive down the road its cold again. Need help here. Is my control panel bad or what?
Submitted: 4 years ago.
Category: Ford
Expert:  Shawn replied 4 years ago.

HiCustomer

 

Thanks for using Just Answer, the most common cause of the problem you are having is a defective Temperature blend door actuator. (Click Here for Instructions). Hope this helps you out.

 

Before replacing the Blend Door Actuator, make sure cooling system is full and there are no air pockets trapped in the system, also while the engine is running make sure both heater hoses are very hot, if one is cooler than the other suspect a plugged or restricted heater core.

 

If the hoses are only getting warm, (must be very hot) suspect a defective thermostat, as long as there is no air in the cooling system.

 

 

 

A/C Electric Blend Door Actuator

 

The A/C electric blend door actuator is located on the plenum assembly.

  • Its function is to move the air temperature blend door on command from the control assembly.
  • The A/C electric blend door actuator contains a reversible electric motor and a potentiometer. The potentiometer wiper is connected to the actuator output shaft and moves with the output shaft to indicate the position of the air temperature blend door.
  • A 5 volt signal is applied to the ends of the potentiometer. The voltage available at the wiper indicates the position of the potentiometer. The expressed value of the actuator wiper voltage is sent to the EATC module and is compared to the desired wiper voltage determined by the EATC module. The control module then drives the actuator motor in whichever direction is necessary to make the actuator wiper voltage agree with the desired wiper voltage.
Customer: replied 4 years ago.
All that stuff works heater hoses are hot and blender door is working fine. I have no air in system.
Expert:  Shawn replied 4 years ago.

HiCustomer

 

If all those things are working properly, then you should have heat in the vehicle, unless the heater core itself is plugged and not generating the proper heat.

 

  • Insufficient, erratic, or no heat
  • Low engine coolant level.
  • Engine overheating.
  • Plugged or partially plugged heater core.
  • Temperature blend door binding/stuck.
  • A/C electric blend door actuator.

 

A/C Electric Blend Door Actuator

 

The A/C electric blend door actuator is located on the plenum assembly.

  • Its function is to move the air temperature blend door on command from the control assembly.
  • The A/C electric blend door actuator contains a reversible electric motor and a potentiometer. The potentiometer wiper is connected to the actuator output shaft and moves with the output shaft to indicate the position of the air temperature blend door.
  • A 5 volt signal is applied to the ends of the potentiometer. The voltage available at the wiper indicates the position of the potentiometer. The expressed value of the actuator wiper voltage is sent to the EATC module and is compared to the desired wiper voltage determined by the EATC module. The control module then drives the actuator motor in whichever direction is necessary to make the actuator wiper voltage agree with the desired wiper voltage.

 

 

INSUFFICIENT, ERRATIC OR NO HEAT

CONDITIONSDETAILS/RESULTS/ACTIONS
Y1 CHECK FOR PROPER ENGINE COOLANT LEVEL
Check the engine coolant level when hot and cold.

  • Is the engine coolant at the correct level (hot/cold) as indicated on the engine coolant recovery reservoir?
Yes GO to Y2.
No GO to Y3.
Y2 CHECK FOR HOT WATER TO THE HEATER CORE INLET HOSE
WARNING: The heater core inlet hose will become too hot to handle and may cause serious burns if the system is working correctly.
NOTE: Be sure that the inlet hose flow restrictor is in place and is undamaged.
Allow the engine to reach normal operating temperature.
graphic
Feel the heater core inlet hose.

  • Is the heater core inlet hose too hot to handle?
Yes GO to Y4.
No Suspect bad thermostat or possible air trapped in the system, or possibly low coolant level.
Y3 CHECK THE ENGINE COOLING SYSTEM INCLUDING RADIATOR CAP FOR LEAKS
Fill engine cooling system to specified level.
Pressure check the engine cooling system;It is not necessary to check the components separately at this time.

  • Does the engine cooling system, including the radiator cap, hold pressure?
Yes GO to Y4.
No Pressure test the heater core.
Y4 CHECK THE HEATER CORE OUTLET HOSE FOR HOT WATER
graphic
Feel the heater core outlet hose.

  • Is the heater core outlet hose cool or cold?
Yes TEST the heater core for a plugged or partial plugged condition.
No

Customer: replied 4 years ago.
It acts like the vent is open when I go down the road. Could the thermostat on the heater control be bad, all the hoses are hot and reservoir is full, everything seems to be right and the core is new? where does the vent come in the fresh air?
Expert:  Shawn replied 4 years ago.

HiCustomer

 

Thank you for asking your question on JustAnswer.

 

The other Experts and I are working on your answer. By the way, it would help us to know:

-Do you have the manual or automatic control?

Thank you again for trusting us with your problem. Please reply as soon as possible so that we can finish answering your question.

Customer: replied 4 years ago.
I have the automatic controls
Expert:  Shawn replied 4 years ago.

HiCustomer

 

Ford did have problems with the EATC (Electronic Automatic Climate Control), however I would first suggest performing the following tests before replacing.

 

Electronic Automatic Temperature Control Module Self-Test

  • The EATC module self-test will not detect concerns associated with data link messages like engine coolant temperature or vehicle speed signals. A NGS tester must be used to retrieve these concerns.
  • The EATC module self-test will detect concerns in the system control functions and will display hard diagnostic trouble codes (DTCs) in addition to intermittent diagnostic trouble codes for concerns that occur during system operation. The vehicle interior temperature should be between 4-32°C (40-90°F) when performing the self-test. If the temperatures are not within the specified ranges, false in-car temperature sensor DTCs will be displayed.
  • The self-test can be initiated at any time. Normal operation of the system stops when the self-test is activated.
  • To enter the self-test, press the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The display will show a pulse tracer going around the center of the display window. The test may run as long as 30 seconds. Record all DTCs displayed.
  • If any DTCs appear during the self-test, follow the diagnostics procedure given under ACTION for each DTC given.
  • If a condition exists but no DTCs appear during the self-test, refer to the Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Improper Operation.
  • To exit self-test and retain all intermittent DTCs, push the blue (cooler temperature) button. The control will exit self-test, retain all intermittent DTCs and then turn OFF (display blank).
  • To exit self-test and clear all DTCs, press the DEFROST button. The vacuum fluorescent display window will show 888 and all function symbols for one second. Then, the EATC control assembly will turn OFF (display blank) and all DTCs will be cleared.
  • Always exit the self-test before powering the system down (system turned OFF).
  • Intermittent DTCs will be deleted after 80 ignition switch ON cycles after the intermittent condition occurs.

 

Customer: replied 4 years ago.
I did run this test and no codes come back
Expert:  Shawn replied 4 years ago.

HiCustomer

 

BLEND DOOR FAILURE
CONDITIONSDETAILS/RESULTS/ACTIONS
A1 CHECK THE ACTUATOR CLOCKWISE OPERATION (FULL COOL)
NOTE: When performing tests, allow time for actuator to move.

Disconnect EATC Module C280 & C281
graphic
Connect a jumper lead between the EATC module connector pins C281-13, Circuit 250 (O) and C280-2, Circuit 729 (R/W). Connect a second jumper lead between the EATC module connector pins C281-26, Circuit 249 (DB/LG) and C280-3, Circuit 57 (BK).

  • Does the blend door actuator motor drive clockwise?
Yes GO to A2.
No GO to A3.
A2 CHECK THE ACTUATOR COUNTERCLOCKWISE OPERATION (FULL HOT)
graphic
Connect a jumper lead between the EATC module connector pins C281-26, Circuit 249 (DB/LG) and C280-2, Circuit 729 (R/W). Connect a second jumper lead between the EATC module connector pins C281-13, Circuit 250 (O) and C280-3, Circuit 57 (BK).

  • Does the blend door actuator motor drive counterclockwise?
Yes GO to A8.
No GO to A9.
A3 CHECK CIRCUIT 249 (DB/LG) FOR A SHORT
Disconnect Electronic Blend Door Actuator C229
graphic
Measure the resistance between the EATC module connector pin C281-26, Circuit 249 (DB/LG) and ground.

  • Is the resistance greater than 10,000 ohms?
Yes GO to A4.
No REPAIR Circuit 249 (DB/LG) for a short to ground. TEST the system for normal operation.
A4 CHECK CIRCUIT 250 (O) FOR A SHORT

 

graphic

Measure the resistance between the EATC module connector pin C281-13, Circuit 250 (O) and ground.

  • Is the resistance greater than 10,000 ohms?
Yes GO to A5.
No REPAIR Circuit 250 (O) for a short to ground. TEST the system for normal operation.
A5 CHECK CIRCUIT 249 (DB/LG) FOR AN OPEN
graphic
Measure the resistance between the EATC module connector pin C281-26, Circuit 249 (DB/LG) and the electronic blend door actuator connector pin C229-8.

  • Is the resistance less than 5 ohms?
Yes GO to A6.
No REPAIR Circuit 249 (DB/LG) for an open. TEST the system for normal operation.
A6 CHECK CIRCUIT 250 (O) FOR AN OPEN
graphic
Measure the resistance between the EATC connector pin C281-13, Circuit 250 (O) and the electronic blend door actuator connector pin C229-7.

  • Is the resistance less than 5 ohms?
Yes GO to A7.
No REPAIR Circuit 250 (O) for an open. TEST the system or normal operation.
A7 CHECK THE ACTUATOR OPERATION
Remove the electronic blend door actuator;
Connect Electronic Blend Door Actuator C229

 

graphic

With the actuator drive shaft disengaged from the temperature blend door, drive the electronic blend door actuator full clockwise; refer to Step A-1.
graphic
With the actuator drive shaft disengaged from the temperature blend door, drive the electronic blend door actuator full counterclockwise; refer to Step A-2.

  • Does the blend door actuator drive both clockwise and counterclockwise?
Yes SERVICE the temperature blend door for a blocked or binding condition. TEST the system for normal operation.
No INSTALL a new A/C electronic blend door actuator. TEST the system for normal operation.
A8 CHECK THE FEEDBACK POTENTIOMETER TOTAL RESISTANCE

 

graphic

Drive the electronic blend door actuator full counterclockwise; refer to Step A2.
graphic
Measure the resistance between the EATC module connector pins C280-6, Circuit 243 (LG/O) and C281-9 Circuit 247 (W/Y).

  • Is the resistance between 5,000 and 7,000 ohms?
Yes GO to A13.
No GO to A9.
A9 CHECK CIRCUIT 243 (LG/O) FOR AN OPEN
Disconnect Electronic Blend Door Actuator C229
graphic
Measure the resistance between the EATC module connector pin C280-6, Circuit 243 (LG/O) and the electronic blend door actuator connector pin C229-5.

  • Is the resistance less than 5 ohms?
Yes GO to A10.
No REPAIR Circuit 243 (LG/O) for an open. TEST the system for normal operation.
A10 CHECK CIRCUIT 247 (W/Y) FOR AN OPEN
graphic
Measure the resistance between the EATC connector pin C281-9, Circuit 247 (W/Y) and the electronic blend door actuator connector pin C229-6.

  • Is the resistance less than 5 ohms?
Yes GO to A11.
No REPAIR Circuit 247 (W/Y) for an open. TEST the system for normal operation.
A11 CHECK CIRCUIT 243 (LG/O) FOR A SHORT
graphic
Measure the resistance between the EATC module connector pin C280-6, Circuit 243 (LG/O) and ground.

  • Is the resistance greater than 10,000 ohms?
Yes GO to A12.
No REPAIR Circuit 243 (LG/O) for a short to ground. TEST the system for normal operation.
A12 CHECK CIRCUIT 247 (W/Y) FOR A SHORT
graphic
Measure the resistance between the EATC module connector pin C281-9, Circuit 247 (W/Y) and ground.

  • Is the resistance greater than 10,000 ohms?
Yes INSTALL a new A/C electronic blend door actuator. TEST the system for normal operation.
No REPAIR Circuit 247 (W/Y) for a short to ground. TEST the system for normal operation.
A13 CHECK THE FEEDBACK POTENTIOMETER LOW SIDE RESISTANCE
graphic
Drive the electronic blend door actuator full counterclockwise; refer to Step A-2.
graphic
Measure the resistance between the EATC module connector pins C280-18, Circuit 246 (P) and C281-9, Circuit 247 (W/Y).

  • Is the resistance between 250 and 1,500 ohms?
Yes GO to A16.
No GO to A14.
A14 CHECK CIRCUIT 246 (P) FOR AN OPEN
Disconnect Electronic Blend Door Actuator C229
graphic
Measure the resistance between the EATC module connector pin C280-18, Circuit 246 (P) and the electronic blend door actuator connector pin C229-1.

  • Is the resistance less than 5 ohms?
Yes GO to A15.
No REPAIR Circuit 246 (P) for an open. TEST the system for normal operation.
A15 CHECK CIRCUIT 246 (P) FOR A SHORT
graphic
Measure the resistance between the EATC module connector pin C280-18, Circuit 246 (P) and ground.

  • Is the resistance greater than 10,000 ohms?
Yes INSTALL a new A/C electronic blend door actuator. TEST the system for normal operation.
No REPAIR Circuit 246 (P) for a short to ground. TEST the system for normal operation.
A16 CHECK THE FEEDBACK POTENTIOMETER HIGH SIDE RESISTANCE
graphic
Drive the electronic blend door actuator full counterclockwise; refer to Step A2.
graphic
Measure the resistance between the EATC module connector pins C280-6, Circuit 243 (LG/O) and C280-18, Circuit 246 (P).

  • Is the resistance between 3,500 and 6,000 ohms?
Yes GO to A17.
No INSTALL a new A/C electronic blend door actuator. TEST the system for normal operation.
A17 CHECK CIRCUIT 243 (LG/O) FOR A SHORT TO GROUND

 

graphic

Measure the resistance between the EATC module connector pin C280-6, Circuit 243 (LG/O) and ground.

  • Is the resistance greater than 10,000 ohms?
Yes GO to A18.
No REPAIR Circuit 243 (LG/O) for a short to ground. TEST the system for normal operation.
A18 CHECK CIRCUIT 247 (W/Y) FOR A SHORT TO GROUND

 

graphic

Measure the resistance between the EATC module connector pin C281-9, Circuit 247 (W/Y) and ground.

  • Is the resistance greater than 10,000 ohms?
Yes GO to A19.
No REPAIR Circuit 247 (W/Y) for a short to ground. TEST the system for normal operation.
A19 CHECK CIRCUIT 246 (P) FOR A SHORT TO GROUND

 

graphic

Measure the resistance between the EATC module connector pin C280-18, Circuit 246 (P) and ground.

  • Is the resistance greater than 10,000 ohms?
Yes INSTALL a new A/C electronic blend door actuator. TEST the system for normal operation.
No REPAIR Circuit 246 (P) for a short to ground. TEST the system for normal operation.
Customer: replied 4 years ago.
where is the a/c actuator
Expert:  Shawn replied 4 years ago.

Hi work 6930,

 

The blend door actuator is located on the plenum assembly. Under the dash, towards the center.(Click Here for Instructions).

 

CLICK HERE FOR COMPONENT LOCATIONS

Customer: replied 4 years ago.
that door is moving just like it is suppose to. dial temp up door opens dial temp down door closes.
Expert:  Shawn replied 4 years ago.
Then the heater should work unless the door is broken, You need to perform the tests I sent you, if everything is checking out then the heat should work. Double check coolant level, make sure it is full with no air in the system.
Customer: replied 4 years ago.
I have found the problem. The intake gasket is leaking right where the heater hose hooks on to the manifold. Thank You
Expert:  Shawn replied 4 years ago.

Awesome good job, it just sounded like the coolant was low

 

CLICK HERE FOR INSTRUCTIONS



Edited by Shawn on 12/19/2009 at 12:43 AM EST
Customer: replied 4 years ago.
let people know that is a big problem with the 4.6 and 5.4, also to check for cracks in manifold right by the hose inlet on the manifold 4.6 is real bad for cracking, not so bad on the 5.4. Talked to a guy that fought one for 2 years for he found it, everything seemed normal but no heat. pass this on to everybody and thanks for trying to help me. I will accept after you read this.
Expert:  Shawn replied 4 years ago.
No problem ,and if you need any more help, let me know.
Shawn, Auto Service Technician
Category: Ford
Satisfied Customers: 3756
Experience: 16 years experience Ford,Nissan and Honda dealership in all areas
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Shawn
Shawn
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