Heating - Air Conditioner problem: Blend door?


I’ve had a problem with my 2003 Taurus’ heater and air conditioner controls for some months now. I do not have climate control - I have the ?3 knob? system: #1-fan, #2-temp control and #3-heater/air conditioner settings. My #1 knob works fine on all settings. All of the settings on #3 work ? the defroster, upper and lower and floor vents are good. My problem is that the #2 knob is stuck in the ?high heat? setting.



In the fall, when I still needed the air conditioner occasionally, I noticed sometimes that when I switched #3 to either of the ?air conditioner? settings from any ?heater? setting I would still get hot air. If I flipped the #3 knob back and forth a couple of times, I?d hear a ?clunk? somewhere in the dashboard area, and then cool air would come out. However, in October, on a 6 hour trip on a 75 degree day, it got stuck on ?high heat? again and took 2 hours to finally let go so we could cool down. Needless to say my husband was sweating bullets and the first 2 hours of the trip were not pretty. I live in upstate New York and thankfully, a few weeks later it got stuck on ?heat? again.



I took the car to my dealer the other day, and they said the problem is my ?blend door?. They quoted me $650 ? mostly labor because they have to remove the steering wheel and dashboard etc. I realized when talking to the ?asst. manager in charge of my case? that the actual ?guy in charge of fixing my heater problem? had never really looked at the car: the two of them had only talked about it.



I thought $650 sounded extreme, so told ?manager guy? to not do the repair and called around to some shops that specialize in heater and air conditioning work. Most said they?d do a diagnostic etc. etc. etc. but that $650 was probably high. However, out of all my calls, only one shop asked if I had climate control. He told me that because I didn?t, the ?blend door? was actually controlled by a cable that can sometimes be fixed without tearing the dash out.



Is this true and who do I believe?

Blend doors were once controlled by cables. Now they are more likely controlled by vacuum or electrical doors. I think the Taurus is electrical. I don?t know why turning knob 3 would cause the blend door to operate. Knob 3 controls doors, via vacuum motors if it is a typical Ford.

Go find a Taurus forum if no one can give you specific answers here. Access to these controls is a problem with lots of cars. If the dash has to be pulled back, it can take several hours so $600 might not be bad. It takes several hours because it won?t be ?torn out?. Lots of stuff needs to be unhooked, unscrewed and unbolted. Then it all has to be put back. If you do have to do this, you might also consider replacing other things in that area that tend to have problems, like the heater core and the vacuum-controlled doors and associated stuff. The costs in parts is a lot lower than going back in there in a year or three. See what the consensus is by posting in a Taurus forum.

Note this, blend doors often fail by breaking a linkage or the blend door motor fails. Very very frequently this is accompanied by rhythmic ?banging? of the door when it tries to move. If the shop has not done any trouble-shooting on this it could be that the ?pot? that control knob#1 is hooked to has gone bad or you have a bad connection somewhere. That could mean that the dash does not have come back and it might cost a lot less than they told you. It might also be that the blend door motor is broken and the blend door is not. The motor is on the outside of the duct and with some cars they can be replaced without a lot of disassembly. If the door is broken, you likely have to get the ducts apart to replace it.

I had to replace a leaking heater core in an older Taurus once and I can tell you I would not do it again, it is a huge job, taking more than a day, with constant reference to a shop manual. (Maybe the second time it would not be so bad.) The blend door was controlled by a cable and you can get to it right away without much effort. I think you could access it by going under the dash without removing anything, but you have to know what you are doing. There is a Taurus owners forum called Taurus Club of America. You can get specific information about your car there.