Thermostat Not working

[brinne19]

I have a '00 EB explorer and have the electronic thermostat, however, the past couple of weeks it has not been working. When i have it on regular settings it only blows out full heat which i cannot leave on for very long, and when i have it on max ac it only blasts out the coldest setting.. this can get very annoying.... i was wondering what is wrong w/ the ac as most the time i leave it off but winter is approachng and it would be nice to have it work. i took it the dealer and they "Said" they fixed it but it still didnt work, i thought it might be the fact that i have neons under my dash... i am running two 12v neons under the dash and tapped a constant 12v wire far under the dash, i was told by a person who works at a dealer that this is a good wire to tap. is it that the wiring of the neons that messes it up, if i take them out will it work... any help is greatly appreciated

-brian

 

[Robb]

Are you referring to the digital heat/ac controls?

If so, I have about the same problem. It would only go into ac when set to 65 or below. I have half fixed it by blowing out the thermistor. It is covered by a little round plastic louver looking thing on my 96. Directly the the right of the radio bezel. By doing this, it will go into ac until the correct setpoint is met. But it still goes directly into heat when it reaches this point. Haven't looked into that part of the problem yet.

Hope this helps a little,

Robb

 

[brinne19]

yeah its the electronic heat control.... i have the exact same problem

 

[Robert]

Sounds like your heater blend door. You are looking at a $800 - $1200 fix if you have Ford do it. Do a search for "blend door" and you'll find out all you need to know. Basically there are two reasons the blnd door can fail. One is that Ford mistakenly installed doors from the manual system into the automatic A/C system. After a while it will break. Second, Ford used to make the doors out of hard plastic. The doors got brittle and would break. Starting in either '98 or '99 Ford started making the doors out of nylon and made sure they put the correct doors in the correct vehicles so after '99 or so they don't break as often.

 

[brinne19]

how would doors have anything to do w/ the ac though?... this confuses me

 

[Robb]

Robert is referring to the blend door which acts as a damper inside your ac/heating ductwork. As your system switches between ac and heat, this damper opens one way and cuts off another way. It is a common problem in early 2nd generation Xs, and is very expensive to fix. It isn't very common in '00 Xs. And since your ac works fine when put into full ac and your heat works fine in heat, I wouldn't think it is your blend door. I would think it is more of a problem with your thermistor or ATC control. But that is just me........

Robb

 

[brinne19]

when i took it to the stealer the mechanic didnt even touch the thing to see if it was workin or not and just said it was ok, what should i tell them to look for, and if its a factory defect i shouldnt have to pay for it under warranty correct?

 

[Robert]

I missed the fact that yours is a '00. It should have the updated parts already. If not though, your symptoms are those of a stuck blend door. The reason you get cold air in Max only is because in Max you close the heater control valve which shuts off all radiator coolant to the A/C-Heater system. If your blend door is stuck in the heater position, all positions except Max will give you heated air, Max will give you maximum A/C. Since there are many more items controlling the automatic A/C though it could be a faulty interior thermistor or even something in the controls that directs which doors are where.

As far as whether or not it would be covered under warranty if it is a Ford defect, only if you are under the standard 3 year/36K warranty. Ford doesn't consider defects when determining if they will warrant an item. They only consider how often it gets reported or if it is a safety related issue before determining whether or not to extend the warranty. So far they haven't extended the warranty on the blend doors.

 

[brinne19]

hey guys thanx for all help i think im just gonna bring in some of these messages and ***** at a mechanic until they fix it, the stealer near my house makes money off of peoples ignorance about cars, its really wrong on so many levels.....