Several months ago I posted a thread about a "buzzing/computer boot-up" type of noise coming from behind the automatic climate control/head unit area.

Since the noise came and went, I didn't worry too much about it. However with the cold weather, I found the climate control would either blast heat or blast cold air between 68 and 72 degress. In other words, even if the truck was fully warmed up and the fan was on the lowest setting the temperature felt like it was 85 degress.

Long story short, I find out through this site that the problem is the temperature blend door acuator. I break-down and take the truck to the dealer and explain the issue in the kindest words what I feel might be causing the problem. I get a call later that day and they tell me the truck is fixed. They replaced the HVAC control head unit with a new one (ignoring what I told them about the actuator) and what do you know the truck was making the same noise on the way home.

I take the truck back to the dealer this morning (blend door actuator TSB in hand) and let the service writer and the tech hear the noise. They both tried to give me the "thata normal" line and I pressed a little harder and asked them to please check out the operation of the blend door acuator and they agreed. I was suprised the tech had no idea what I was talking about being that this seems to be a common issue many are experiencing.

I have not heard back from the dealer yet. I will post another update when I get it back.

If any of you are having climate control issues the problem is most likely the temperature blend door acutor and not the hvac control unit.

 

I have heard of that TSB too. Even though I have manual climate controls, mine makes a high pitched screeching sound when I change the temp. I guess the TSB calls for some light lubricating grease to help it move. I hope mine never fails, as I am out of warranty, and I'm sure the blend door is buried in the dash.

 

I had the TSB done and it now works great. They replaced the door and door motor. I also had to go back twice. It is alot of work, they have to drain the coolant slightly. I cannot believe how tight everything is packed in there.
I had the repair done last April, and is HVAC is working great !!

 

Did it make any noise before the TSB fix? I'm hoping mine doesn't get stuck LOL.

 

I got the truck back today. The dealer apologized for the mistake and suprised me with a free detail. The HVAC now works great and I don't have to listen to any strange noises. Here is the TSB:

08-23-6
EATC - INTERMITTENT WARM AIR OUTPUT TEMPERATURE SET 68-72 F (18-22 C)EMTC - INABILITY TO CONTROL TEMPERATURE OUTPUT
Publication Date: November 3, 2008
FORD:
2005-2008 F-150LINCOLN:
2006-2008 Mark LT

ISSUE:

Some 2005-2008 F-150 and 2006-2008 Mark LT vehicles equipped with Electronic Automatic Temperature Control (EATC) may exhibit intermittent periods of warm air output in Auto mode with the temperature control set between 68-72 degrees Fahrenheit (18-22 degrees Celsius). Some 2005-2008 F-150 vehicles equipped with Electronic Manual Temperature Control (EMTC) may exhibit periods where the cabin temperature cannot be maintained with the control ****. Some customers may also complain the heat cannot be reduced without rotating the control **** well into the Cool/Blue range.
ACTION:

Refer to the following Service Procedure to correct the condition.
SERVICE PROCEDURE



The condition may be caused by a faulty temperature blend door actuator.
Check actuator activity.
EATC systems may be monitored with the IDS PID (LBLNDPOS).
EMTC systems may be observed through the right side of the instrument panel with the glove compartment door positioned downward.
Erratic PID activity or an actuator that appears to be erratically hunting for correct position during the condition should be replaced. Refer to Workshop Manual, Section 412-01, for removal and installation details.
NOTE:THE IGNITION KEY MUST BE OFF WHEN REPLACING THE ACTUATOR. ENERGIZING THE ACTUATOR BEFORE INSTALLATION ON THE HEATING VENTILATION AIR CONDITIONING (HVAC) CASE WILL CAUSE THE PART TO BECOME MISS POSITIONED AND CORRECT ORIENTATION WILL BE LOST. INCORRECT ACTUATOR OPERATION MAY RESULT.
PART NUMBERPART NAME9L3Z-19E616-EActuator - Motor Asy

WARRANTY STATUS:

Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.
OPERATIONDESCRIPTIONTIME082306A2005-2007 F-150, 2006-2007 Mark LT: Replace The Temperature Blend Door Actuator. (Do Not Use With 19700D, 19700D6, 19616C, 12650D)0.7 Hr.082306A2008 F-150, 2008 Mark LT: Replace The Temperature Blend Door Actuator. (Do Not Use With 19700D, 19700D6, 19616C, 12650D)0.5 Hr.
DEALER CODING

BASIC PART NO.CONDITION CODE19E61642
NOTE: The information in Technical Service Bulletins is intended for use by trained, professional technicians with the knowledge, tools, and equipment to do the job properly and safely. It informs these technicians of conditions that may occur on some vehicles, or provides information that could assist in proper vehicle service. The procedures should not be performed by "do-it-yourselfers". Do not assume that a condition described affects your car or truck. Contact a Ford, Lincoln, or Mercury dealership to determine whether the Bulletin applies to your vehicle. Warranty Policy and Extended Service Plan documentation determine Warranty and/or Extended Service Plan coverage unless stated otherwise in the TSB article. The information in this Technical Service Bulletin (TSB) was current at the time of printing. Ford Motor Company reserves the right to supercede this information with updates. The most recent information is available through Ford Motor Company's on-line technical resources.
Copyright © 2008 Ford Motor Company
<IMG height=1 alt="" width=1 border=0 name=s_i_fmcptsprod> maybe this will help