De-evolving ATC

[85crownHPP]

I think Id rather have direct control of the blend door, rather than try to figure out why my ATC never worked.
It never blew very hot, and it used to make for cold winter road trips. Silly me didn't know you could unplug the blend door vacuum line (behind the glove box) for full heat.

I would assume the vent selector stuff would be the same, but has anyone seen the differences in the blend door controls for ATC and non?
I bet ATC is a big ol mess.
I know the blower resistors are different, due to the 'auto' setting. I just hope this wouldnt involve re-wring that, then it may be easier to figure out whats wrong with it... Id rather have non ATC .... like a manual transmission for the climate control. yeeeeeeeeeah

Anyone ever fixed a poor heat probelm???

Should I fix or simplify???

[grandpaslincoln]

I've got a heat problem as well, it used to blow hot and fast, now the air doesn't come out as hard. I pulled the glovebox door and looked behind there, put it back on and walked away. Too many vac line and shit in there. Maybe someday I will work up the courage to tear into it, but it looks fairly involved. Definately not a one day job.

If you can simplify it, I say go ahead, but it may not be any easier to do than to just fix the thing.

[boXman]

The heat problem is that little blue sensor above the glove box area. I forget the name now, could be as simple as "atc sensor". I beleive it's accesible by removing the dash pad, the trim doesn't have to come off.

[85crownHPP]

WELL....

I just looked at a Non ATC system at the junkyard, and as suspected the blend door is 100% direct cable operated... so it looks like I might have to replace the whole blend door assembly!!!! No thanks... I might try cleaning the ATC sensor...

There is one glimpse of hope however, if the vacuum controll for the ATC blend door happens to pull on a cable that opens the door... and does not directly controll the door with vacuum. Ill have to take a closer look at mine and see... anyone know??? There is a lot of space in the non ATC car where the vacuum gizmo would be... so it may just be this way.

[gadget73]

cable controls the vacuum gizmo, and that operates the servo. Its really not as horrible and complex as you might think it is. The book says the test for it is a vacuum guage. If, when set to full hot, you have more than 3" of vaccum at the clear hose, replace the sensor. Thats pretty much all there is to it. I have a post on here somewhere with the correct number, it'll cost you about $45 for a new one.

[86GmLsCoupe]

I just replaced mine and it ran me and 30 with shipping. It took about and hour and a half for me to do. The fastener locations were very akward (two screws) but when all was done the climate control worked fine. This is my third sensor in the car and have no clue why then go so fast. Anyone know of service bulletins regarding the sensor?

Also added some pics of the ATC install

1986 Grand Marquis LS - coupe [/url] http://photos.yahoo.com/leo76830

[gadget73]

I guess maybe I should have shopped around online for the thing instead of going to the dealer. They still make them, the part I installed was dated 2005. The one I pulled was dated 1997. It seems to not be a very durable part.