97GRMARQ

I'm looking into purchasing a 1997 Grand Marquis-everything in good condition,except that the "digital" control doesn't turn on the a/c.When I click the temp to the lower #'s it still blows hot . I pressed the defrost button & the compressor did kick on(and off occasionally) under the hood ,but yet the interior was still blowing hot (not even warm) air?
Is this just a problem w/the digital control and replacing the complete control will correct it ,or the heater actuator/door etc.can also be defective,or maybe something else?
The old owner mentioned "he'd go to someone in the beginning of each climate change & the guy would switch something (do something),and then the cold air only would work,vise versa in the heating season. Please help!

thundercougar

sounds like your electronic blend door actuator is bad.in most case the dash has to be removed or at least loosened enough to pull foward to replace it. U can run a self test on digital climate control.It ill display a number and that number represents the problem.I might be able to tell u how I just have to check your spec.Is it full digital or part digital as in does it have some knobs on it?

97GRMARQ

Does it pay to 1st try switching the digital control box,or you think it's definitely the blend door itself broken, or maybe the blend door actuator?
(I assume since he had ac in the summer,the door itself isn't broken,and it probably is the actuator, or maybe the digital control is no good-but the buttons all click & change settings on the display when pressed [ALL DIGITAL-NO KNOBS] ? )
Also,would you exactly know (pictures,etc.) what the guy maybe was doing before the summer and before the winter to change from all cooling to all heating? Was it manually closing & opening the blend door or was he switching wires on the control? Would anyone know exactly where it's located? How to get to it?

thundercougar

i would run the self test first.its easy.try this. press off and floor at same time then automatic within two seconds.it will run a test.afte about a minute if anything is wrong it will come up as a number.#24 is blend door

97GRMARQ

Do you mean to do this on the heater ac control without any computer hooked up? I tried it
w/out a computer code reader-by pressing off and floor at the same time and then pressed automatic within 2 secs after I left go of the "fl"&"off" buttons-while the engine was on----
no number showed up on the digital display of that control (the display on the control that I was pressing those buttons). Do I have to continue holding the 1st 2 buttons when I press "automatic",or you meant the number would show up on an external computer diagnostic code reader ?

thundercougar

Start the car.then run it.press floor and off ant same time.then release.within 2 seconds press automatic.u dont need a code reader.it is programmed on the digital heat/ac control.the number will display on the control module.let me double check to make sure that its the right way to run the test.there are several.

97GRMARQ

I did it exactly as you state . Nothing happened. Can it be that this electr control is an older model? The control was manuf. in 1996.

thundercougar

I have a 96 and it works with mine.There are just several differeent app. for some cars.Let look thru my manual to try to do it another way.

97GRMARQ

Blend Door Motor Was The Problem- Had To Replace It-Everything IS NOW Working OK.