Fox T-Bird/Cougar Forums

Technical => Electrical Tech => Topic started by: V8Demon on April 04, 2019, 11:01:25 AM

Title: Well then...... That's news to me.....
Post by: V8Demon on April 04, 2019, 11:01:25 AM
I was doing a little digging into EATC system operation and came across the following thread.....

http://www.foxtbirdcougarforums.com/index.php?topic=39114.msg451153#msg451153

I found a post in there that piqued my interest considerably.  Here it is....

Quote from: My10-80;451112
would it make a difference that I can still manually adjust the speed?
Ummmm, I dunno I'd suspect the controller I mentioned is OK if manual adj works...

May want to check EATC temp sensor mounted at heater core hose connector... It prevents blower from operating on automatic when engine is cold, then goes to full on once temp starts to rise... It's one of the things that pissed me off about the EATC system, as air was never warm enough when high speed activated(and part of reason why I specifically sought out my TC with a manual HVAC system)... Then you are talking about A/C, so again I dunno...

BTW there is also a cabin ambient temp sensor that plays a large roll in operation, it's mounted in dash above the Graphic EQ/storage well...


I'm sorry.....  WHAT? A cabin temp sensor?!!!!?????

 I never knew about this let alone noticed it when I've been messing about in that area.... 
Someone please educate me on it.
Title: Re: Well then...... That's news to me.....
Post by: thunderjet302 on April 06, 2019, 12:23:00 AM
Well it's there. I've seen it when the radio surround trim is off. I haven't tried to remove it but the thing works, which is all that matters to me.
Title: Re: Well then...... That's news to me.....
Post by: V8Demon on April 12, 2019, 08:54:49 AM
I'm curious about its operation more than anything else....  Meh.  Time to pony up for that shop manual I've been eyeballing anyway....
Title: Re: Well then...... That's news to me.....
Post by: thunderjet302 on April 12, 2019, 10:29:14 PM
According to pages 108-109 of the 1988 EVTM there is an in car temp sensor in the dash as well as an ambient temp sensor in the evap case. So the system has two temperature sensors.
Title: Re: Well then...... That's news to me.....
Post by: V8Demon on April 14, 2019, 09:05:44 AM
The dash one is what I'm interested in. 
Title: Re: Well then...... That's news to me.....
Post by: mcb82gt on April 18, 2019, 11:23:13 AM
News to me  also.  I just knew about the one monitoring coolant temp to the heater core.
Title: Re: Well then...... That's news to me.....
Post by: jcassity on May 11, 2019, 12:10:02 PM
guys,
the trim around your radio & ash tray & eatc ,, at the top rolled in area of that piece of trim there is a cut out from the factory.
poke your finger into that approx 3/8'' x 1'' opening and you may find the j or k wire type temp sensor leads.

on my 20th the sensor is not there,, its on deeper into the innerds of the dash.  the factory wire would not reach its intended home.

Its used when you set your eatc to Auto,, the eatc will ramp the blower up and down on its own? 

i did not know about an external temp sensor other than the one on the heater core

Title: Re: Well then...... That's news to me.....
Post by: V8Demon on October 14, 2019, 04:06:07 PM
Been busy as heck.  Forgot all about this.  My shop manuals came in.  Time to research this.  I'll post when I can.
Title: Re: Well then...... That's news to me.....
Post by: V8Demon on December 09, 2019, 08:34:58 PM
Please click on the two links.  They're pictures.  Haven't quite figured out how to insert the actual images from Google Drive on here yet.

https://drive.google.com/file/d/19Og6H_pz0fwbPkZmkHo8dYZQOxhOh8hl/view?usp=sharing

https://drive.google.com/file/d/19PDau6qmuW03rjb6roA6q8oj1_8p-yKl/view?usp=sharing

Sorry for the long wait.  I actually pulled the In-vehicle sensor today and cleaned it.  It was quite disgusting.
It may even be so bad that it no longer works.  I'm looking through the test procedures in the shop manual now. 

Anyway, whether or not I'll need them does ANYONE actually know the part numbers for these or the Motorcraft numbers?  I know they're quite difficult to come by. 
Title: Re: Well then...... That's news to me.....
Post by: EricCoolCats on December 09, 2019, 10:13:05 PM
EATC ATC HVAC A/C Temp Sensor - 1985-1990 Thunderbird, Cougar - Motorcraft YH-434
eBay link: https://www.ebay.com/itm/Motorcraft-YH-434-EATC-ATC-HVAC-A-C-Temp-Sensor-1985-1990-Thunderbird-Cougar/184006024335?fits=Make%3AFord&hash=item2ad79d1c8f:g:8a0AAOSwONddsIIp

1984 - 1989 Lincoln Mark VII A/C Ambient Air Sensor - E4LY-19E642-A
eBay link: https://www.ebay.com/itm/1984-1989-LINCOLN-MARK-VII-A-C-AMBIENT-AIR-SENSOR-ASY-NEW-OLD-STOCK/133131113286?hash=item1eff3b9346:g:puMAAOSwqLFdQwhZ
Title: Re: Well then...... That's news to me.....
Post by: BCA on December 10, 2019, 11:28:43 AM
FWIW, the factory sensor in my car looks just like the one in the eBay link that is listed for the Mark VII.
Title: Re: Well then...... That's news to me.....
Post by: 50RACER on December 10, 2019, 07:51:46 PM
Man! When I am parting out cars, I've just been throwing those away! I didn't know what they were.  Gotta keep 'em now! 
Title: Re: Well then...... That's news to me.....
Post by: V8Demon on December 11, 2019, 03:26:48 AM
Found the following:

https://www.thelincolnmarkviiclub.org/phpBB3/viewtopic.php?f=22&t=11677


Quote
EATC - Redesigned Replacement Control Head

AIR CONDITIONING - ELECTRONIC AUTOMATIC TEMPERATURE CONTROL (EATC) - SERVICE TIPS FOR REPLACEMENT OF
REDESIGNED CONTROL HEAD - VEHICLES BUILT BEFORE 4/21/90

FORD:1985-88 THUNDERBIRD
LINCOLN-MERCURY: 1984-87 CONTINENTAL
1984-90 MARK VII
1985-88 COUGAR

ISSUE:

The EATC control was redesigned in April, 1990. It has a center mode button labeled "VENT" and requires a new ambient temperature
sensor calibrated to match the new control. Using the wrong sensor will bias the interior temperature 5-10~ F from the set point.

ACTION:

If an old level EATC control head is replaced with a new level control head, a new ambient temperature sensor (F0LY-19E642-A),
identified by a white plastic body, must also be installed.

If a vehicle equipped with the old level control head (center button labeled "A/C") requires a new ambient temperature sensor assembly, use
(E4LY-19E642-A), identified by a black plastic body.

If the (E4LY-19E642-A, black body) sensor is not available, use of the (F0LY-19E642-A, white body) sensor will require installation of a new EATC
control head.




 I cannot confirm anything with regards to accuracy of that yet.....  Still hunting for the actual source as the person who posted it didn't cite anyone or anything.

*EDIT*

Might be from here.....

https://www.justanswer.com/ford-lincoln/7yps8-lincoln-mark-vii-lsc-1989-lincoln-mark-lsc.html

Quote
Answered in 17 minutes by:8/28/2013
Lincoln Mechanic: Don - Mo Lurch
.

sorry for the delay.............

.

The Ambient Temperature Sender is located Behind Center Of Radiator Grille under hood.

There was also a TECH Bulletin for replacing the Electronic Automatic Temperature Control (EATC)

The EATC control was redesigned in April, 1990. It has a center mode button labeled "VENT" and requires a new ambient temperature sensor calibrated to match the new control.

Using the wrong sensor will bias the interior temperature 5-10~ F from the set point.

If a vehicle equipped with the old level control head (center button labeled "A/C") requires a new ambient temperature sensor assembly, use (E4LY-19E642-A), identified by a black plastic body.

If the (E4LY-19E642-A, black body) sensor is not available, use of the (F0LY-19E642-A, white body) sensor will require installation of a new EATC control head.
Title: Re: Well then...... That's news to me.....
Post by: thunderjet302 on December 11, 2019, 08:40:08 PM
EATC ATC HVAC A/C Temp Sensor - 1985-1990 Thunderbird, Cougar - Motorcraft YH-434
eBay link: https://www.ebay.com/itm/Motorcraft-YH-434-EATC-ATC-HVAC-A-C-Temp-Sensor-1985-1990-Thunderbird-Cougar/184006024335?fits=Make%3AFord&hash=item2ad79d1c8f:g:8a0AAOSwONddsIIp

1984 - 1989 Lincoln Mark VII A/C Ambient Air Sensor - E4LY-19E642-A
eBay link: https://www.ebay.com/itm/1984-1989-LINCOLN-MARK-VII-A-C-AMBIENT-AIR-SENSOR-ASY-NEW-OLD-STOCK/133131113286?hash=item1eff3b9346:g:puMAAOSwqLFdQwhZ

So the one for our cars (the black 84-89 one) is just a resistor and some other component. Figure out what they other component is and a rebuild is a simple 5 minute solder job.
Title: Re: Well then...... That's news to me.....
Post by: BCA on December 12, 2019, 02:56:33 PM
I cannot confirm anything with regards to accuracy of that yet.....  Still hunting for the actual source as the person who posted it didn't cite anyone or anything.

That reads very much as if it was taken directly from a Ford TSB page.
Title: Re: Well then...... That's news to me.....
Post by: thunderjet302 on December 13, 2019, 11:20:49 AM
EATC ATC HVAC A/C Temp Sensor - 1985-1990 Thunderbird, Cougar - Motorcraft YH-434
eBay link: https://www.ebay.com/itm/Motorcraft-YH-434-EATC-ATC-HVAC-A-C-Temp-Sensor-1985-1990-Thunderbird-Cougar/184006024335?fits=Make%3AFord&hash=item2ad79d1c8f:g:8a0AAOSwONddsIIp

1984 - 1989 Lincoln Mark VII A/C Ambient Air Sensor - E4LY-19E642-A
eBay link: https://www.ebay.com/itm/1984-1989-LINCOLN-MARK-VII-A-C-AMBIENT-AIR-SENSOR-ASY-NEW-OLD-STOCK/133131113286?hash=item1eff3b9346:g:puMAAOSwqLFdQwhZ

So the one for our cars (the black 84-89 one) is just a resistor and some other component. Figure out what they other component is and a rebuild is a simple 5 minute solder job.

Is the other component a thermistor? Anyone have one they can check the markings on? If the only two components on the sensor are a resistor and a  thermistor those are available from multiple sources. Just need the values and it's a simple unsolder the old components, solder in the new, and it's done. It's probably a couple cents in parts. 
Title: Re: Well then...... That's news to me.....
Post by: V8Demon on December 16, 2019, 09:36:40 AM


That reads very much as if it was taken directly from a Ford TSB page.

Indeed it does.  I just can't confirm it at this point.
Title: Re: Well then...... That's news to me.....
Post by: BCA on December 26, 2019, 12:42:51 PM
I found some time to pull mine out of the dash and found out that my memory is not what it used to be as my sensor is not the Mark VII version as I thought.
I'm tempted to buy one of these for the spare parts bin.



Title: Re: Well then...... That's news to me.....
Post by: V8Demon on December 31, 2019, 02:40:35 AM
My hunt for a clean one for the heater box continues along with an NOS brake prop block for a rainy day....