No AC just heat - help

[mrflint]

Hi Friends,
My 2002 is blowing hot air in all settings. Had the AC serviced and tech said its full and showed me icy cold plumbing and then touching the top of ducting under dash was air conditioned cold. He declined to do anymore stating its a known ford problem. So I started my own diagnosis based on what Ive read here and TCA forum. Took radio out, its still connected. Took out blend door actuator and adjusted from heat to cold, it moves about 1/3 a turn and goes full direction every time, its also turns strong, not the problem. Next looked at blend door, the door has a fully cut "D" slot and it seemed to fully seat and hold the blend door actuator shaft. I can manually force the door to full up and down positon by pushing the linkage. It makes no dfference its still hot air coming out in all settings. When the door is rotated up and held for a few minutes I can feel icy air coming from seams in the duct, but no ac coming to vents. The blend door was always 30 seconds to respond but I lived with it. In past month it would thump up or down (noise is normal)a few times at startup but then no more till engine was shut off for a while; stil had no ac. I don't think blend door is problem since I can manually move it and nothing happens

What am I missing? Is there linkage or vacuum somewhere that can be wrong? Thanks for helping

[mwt47]

Do you have electronic or manual controls

Mike

[Davescort97]

On your heating/air conditoning the blend door is vacuum operated. On some settings such as defroster heat the air flow goes through the A/C evaporator before it goes through the heater core. This is to get the moisture out of the air so that it gets the moisture off the windshield. On some of the other heatiing controls the A/C comes on also with the heat. I don't think the door is closing all the way on the blend when just the A/C is on. Either that or the switch on the dash is not working right. I'd check the vacuum hose for looseness but, when the vacuum is not present at all the system goes to heated defrost as a default. Your A/C is all right (you know this). Off hand I'd say you aren't getting enough vacuum or the control on the dash is bad.

[shorod]

Agreed. You need to make sure the blend door is working properly, along with the A/C Evaporator Case Damper Door. In the case of your Taurus, the blower motor always blows air through the evaporator core, regardless of setting. From there, the blend door adjusts how much air flows through the heater core. The damper door also helps meter the air through the heater core.

If you have the electronic controls as mwt47 suggests, you can have the controls perform a self test and possibly alert you to the issue.

Just out of curiosity, how high is your instrument cluster temp gauge getting?

-Rod

[mrflint]

Hi all, thanks for responding. I have manual controls, and the temperature stays in the mid range all the time. The blend door actuator covers kinkage that goes to a lower door, i think its the secondary blender door? I found that by pulling upward on this lower door it would get colder out of the dash vents but not much. I'm going to try some damp soapy water arond the vacuum lines on the functions switch looking for lair leaks

[shorod]

The linkage probably connects to the evaporator case damper door. The damper door is located lower in the case relative to the blend door. Nearly straight below the blend door.

-Rod

[argue01]

Hi All, I have a 2000 Taurus with electronic controls and have the same problem. It always blows full hot air no matter what the selection.
Does any one know if there was ever a service bulletin issued by Ford for this problem? Thanks

[dougyfd]

I have a 99 sable that had the same problem. I'm not aware of any tsb on this. You can try resetting the control head. Press off & floor simultaneously then auto within 2 secs. If there are trouble codes they will display. mine displayed 888 which the service manual states that system is OK. Mine has worked correctly since resetting. Good luck!

[argue01]

dougyfd,

I actually tried the reset procedure yesterday (read it on another forum). I also got the same code 888, but never got a chance to run the car until today. Guess what, the whole system reset and works good as new!
I can't believe it. Do you know how long I have been putting up with this.
This forum rocks and you people rule!

Thanks so much!

[DCooper]

I have a '99 Taurus, ~ 106K miles, with the same problem. I did what Dougyfd said, and it's fixed!! No code displayed, just dashes.

Thank you!

[argue01]

Actually, it worked when I tried the reset the first time but now its back to the same old same old. It displays either code 024 or 025; usually 024, and blows nothing but hot air.
So what now, do I fix it myself and if so is there a good manual I can use or do I take it to the dealership.
I understand there is a TSB out for this problem 02-23-6.

Thanks for the help.

[shorod]

I don't find a LFC of 025, but the 024 is "Temperature Blend Door Failure or Short."

-Rod

[argue01]

Due to everyones great help on this forum I know what the problem is.
Its the fix now. How do I solve the problem?
Can I do it myself or does it need to go to the dealer?

[mrflint]

Hi All, myTaurus still has a problem. When the weather turned cold, the AC seems to partially work. Its a medium AC cold, and can switch between heat and cold. I tried it in closed garage and sure its really AC working and not just cold weather. My car has manual controls with no codes. I did check the vacuum lines connected to switch (ac, vent, heat -selector) and none appeared to leak. I was using warm sopy water at switch connections looking for bubbles, none found. When swithch was turned, you do hear the sound of vacuum applied. I did not follow the lines to the end, perhaps vacuum switch is failing.

[shorod]

Are you saying you're sure the A/C is working just based on temperature, or did you confirm that the A/C compressor is engaging? Do you have your Defroster on by chance? The defroster will engage the A/C compressor to dehumidify the air. As long as the ambient temperature is above freezing, the compressor will still be able to kick in if requested.

-Rod