eatc fixing

[Mark in PDX]

Ok-
I tried this and think maybe i posted it in the wrong place.-

I have a 95 EATC, I also have 2 95 EATC's out of a couple Lincoln.. They are slightly smaller and the fan is backwards when plugged into my SHO.. But my nice 95 EATC has died..
I may have a doner EATC out of a 93 to use to fix it.. but I got curious.
I looked in the 95 lincoln eatc's and all the circuit boards & secondary boards are the same.. There appears to be 1 relay that is different than on the SHO board.
Has anyone done anything more recent than the thread that is 2+ years old about these? Anyone have directions for modifying one of these for use in our cars?
I am going to try to repair the 95 with the 93, following that threads directions, but would really like to know how to repair it w/ the 95 parts since they are newer.
Help?
Mark

 

[NoSlo]

Very easy fix if you have a little soldering skill and patience.

You didn't say how the 1995 EATC died, but if the faceplate is OK and the main circuitboard and solenoids are bad, the easiest fix would be to use the 1993 circuitboard on the 1995 face. Just unsolder the two ribbon cables from the old unit and solder them to the new one.

The only useful part on the non-Taurus units will be the faceplates. If the 1995 EATC face is bad, replace it with the Lincoln faceplate by soldering the ribbon cables in the same way. You may have some fitment issues (need to remove tabs, some space around the unit in the dash), but it will work fine.

 

[Mark in PDX]

Yeah, I can do the soldering, that won't be a problem.. But the fact that when I plugged the Liconln EATC into my car and it appeared to work other than the fan being backwards (up being off instead of hi and down being hi instead of off) made me wonder if there isn't more commonality between these than has been played with in the past.
It was something on the circuit board that died as far as I can tell. It was getting sporadic when hot, would just reboot or not come on at all.. Acted like a cold solder or loose connection- pulled it 1x and re-seated everything and it worked fine for a couple days then got worse.. The display lights up but the self test won't pass. leaves it 1/2 on the screen... So I am assuming circuit board..
Has anyone taken the relay off a suspect 95 SHO board and put it on the Lincoln board and seen if that turns it into SHO board? The boards & all other parts are identical on the 95's I have.. I checked really carefully and can't find any other differences on the boards.
Thanks
Mark

 

[NoSlo]

The difference is the blower control module (on Lincoln Continentals): on the Taurus the fan connects to +12v on one side and the BCM on the other (the BCM controls how much current sinks to ground) On the Continental, both wires of the fan connect to the BCM. The fan control output operates differently because of the BCM.

Other differences in the 1995 continental & taurus EATC make them incompatible. Taurus EATC is directly wired to the Cold engine lockout switch, dimmer lights, whereas the Continental gets this info + speed from the digital bus. Pin 25 of the Taurus EATC goes to the AC clutch; Pin 25 of the Continental EATC goes to the A/C pressure switch, etc.

 

[Mark in PDX]

This confuses me as I did blithely plug it in and it worked except for the fan being reversed. My AC came on and seemed to work, vents changes, outside temp worked.. Automatic didn't because of the fan.
Do you have schematics I could reference to figure this out? I've just been told in the 'yes you can use any eatc' thread that this one is the ONLY eatc that WILL work, so now am confused...
sigh
welcome to FORD.

More info on the BCM? is this a relay chip? or an actual control module outside the box.. All parts inside the boxes I have were identical down to 1 relay control box thing on the board.. I mean, the relays on the vacuum end were IDENTICAL to the 95 sho..
let me know.
Mark

 

[jelloslug]

Pick up a Ford EATC diagnostic manual off of ebay. They have tons of info on how the various Ford EATCs work.