Yes, you can use ANY eatc!

[drdave]

Jaxon,

You are essentially correct, but I do change the whole front of the unit, not just the faceplate. I scoped out the button/display board of new units and discovered that they are exactly the same as the old. Since all eatc units, old and new, use the same housing, what really changed was the electronics. The faceplate is the same size, but it doesn't line up with the old buttons.

The original units used a two-board design. One for the buttons and display and one for the lights. The new units use a board that houses the buttons and lights. But this board is 100% compatible with our units.

So it's not a big mystery, old back end and completely new front end. It does require de-soldering 34 wires and re-soldering 16. All of these wires are part of two ribbon cables. The ribbon cables on the new unit are a bit larger so they have to be modified a little.

But the bottom line is that when you are finished, you can hand this unit to anybody and it would be impossible to tell that the unit has been modified. Looks and works exactly like stock.

I think that what we have all been searching for is a way to use any eatc that we want, and this is by far the easiest way. With the right equipment, you can do this mod in under an hour.

If anyone is still interested, I will gladly post a step-by-step description of how to upgrade your eatc.

DrDave

 

[ohioshodude]

dave my man! i tired to figure out what each wire did once and gave up just couldn't figure out how to test each wire and how to find out what each one did! i knew if someone would figure that out it would work. good job!! I'M very glad this isn't a bs post! also i sugest that people of 92 and older head units upgrade to the newer 93+ units. the electronics are quicker to respond. dave you are great!! i'm so glad someone figure out that wiring. i'd love to have a diagram, i'd even be willing to photoshop a diagram up so all sho folks can have it!

a great day in the sho world, mad props to you dave that must have been a bitch to figure out!

<small>[ June 08, 2003, 03:01 AM: Message edited by: ohioshodude ]</small>

 

[drdave]

No secrets in the SHO world. We all have 100K+ cars because everyone freely shares their knowledge.

I originally started playing with the eatc because I wanted to reprogram the logic to work better with retros to 134a. In my 90, when I would get caught in traffic, the AC would start to get warm and then go to high speed. I was going to reprogram the unit to go to low speed MAX first to try and keep the interior cool.

Then I started playing with installing a relay inside the unit so that when you depressed the outside temp button, the outside temp would stay on the display indefinitely until the button was depressed again.

So I mapped out all of the electronics. It only took about 30 minutes or so to map out the relationship of the buttons and the display to the ribbon cables. They do not work in any logical fashion. But they do work, and I guess that was the desired result.

Transforming these units is not too difficult. The button boards of the newer units are a multi-layer design, so it's a little more difficult to pull the solder from the board. I have a portable electronic de-soldering station in my garage, so I think it only took me about 45 minutes or so to completely change the unit.

I hope that this information helps all of you that have purchased the hard button units, only to find that the fan never turns off. It will now!

 

[drdave]

Jeremy,

Let me know the next time you're in the Metroplex. I'll do yours while you wait. No charge. Have you on your way in under 1.5 hours including install. You'll just have to deal with three little ones jumping all over you until I'm done.

SloSho, here are a couple of bad action photos for you.

David

<small>[ June 07, 2003, 03:04 AM: Message edited by: drdave ]</small>

 

[ohioshodude]

drdave:
Then I started playing with installing a relay inside the unit so that when you depressed the outside temp button, the outside temp would stay on the display indefinitely until the button was depressed again.

drdave did you figure that out? that was my next project. the newer eatc's have this option and i'd love to have it in my sho!

 

[Shoman594]

David you are the man! I would love to do this on my SHO! Could you post the instructions? I cant wait to get started! Sounds like you know your way around electronics, I like the idea of the outside temp saying on. HOW about this, is it possable for you to make the unit display the inside temp from the temp gauge in the small vent ? Dave you are the man, props to you!!!!

 

[BlackOnBlackATX]

Dave, this is phenomenal! i have a new EATC coming to me with all the same buttons as our SHO EATCs have (max a/c, vent, panel/floor, floor, floor/defrost, defrost). this will be a nice addition when you post the procedure! thanks so much for doing this and sharing!
Bob

 

[Jr's Sho]

For those who want their outside temp. to display at all times, I believe Paul found a way to do that. You could probably search and come up with how.

 

[drdave]

Paul's procedure requires that you use an external switch. I like it to be more stealth. Just my personal preference.

As far as displaying the inside temp from the small vent, this would not be practical. Since the sun is always heating the dash, when the air passes through the opening it gets heated. The displayed temperature would not be accurate. This also would require an extra switch or button if you wanted to be able to display the outside temp as well.

I will post the procedure tonight, hopefully with pictures.

<small>[ June 07, 2003, 03:28 PM: Message edited by: drdave ]</small>

 

[drdave]

Well, here is the procedure. It is really quite simple. This information is presented with the expectation that you possess average/above-average soldering skills.

Disassemble the old and new EATC units. This is four screws and two connectors each. Remove all of the electronics from each unit. The display PCB on the new unit will probably be held in place by 5 small Torx screws. Remove these screws.

De-solder the two eight-pin ribbon cables from each display PCB. De-solder or cut the two-pin ribbon connector for the light box on the old unit, as it is no longer necessary. The display PCB on the newer units is a multi-layer design, so be careful.

The ribbon cables on the new units are several millimeters larger than the ribbon cables on the old unit, so you have to modify these. You can overcome this in a number of ways, but I will explain what I did. Make a slit in the insulation between all of the wires about a quarter of an inch long. I did this on the smaller cables that are still connected to the main PCB of the original EATC. This will allow you to spread the wires enough to connect to the new display PCB.

Just so it’s clear, you will be using the main electronics of your old unit and the display and buttons of the new unit.

After the wires are re-soldered, install all of the electronics into the new unit housing and put it back together.

After dealing with many different EACT units, I found that Ford used many different designs on the electronics. I have four different styles. The only thing that remained constant was the wiring of the display boards, which is why I chose to modify units in this way. If you have the newer hard-button unit, the face from a late model Crown Vic (as pictured in my first post) should just snap into place without any need for modification.

Good luck to all.

 

[ohioshodude]

drdave how does that work? the old units have 14 pins including the lights where as the new boards have 16 pins including the lights. you can't just guess where each wire goes and just leave two off. i found which wires goes to the lights on the new switch board but that is where i gave up. shrug also you may know this, what is that chip for under the LCD (i know it's the other one can't think of it, hehe) on the pre 94 switch board? i figured it was important.

OMG i just made a discovery. two years ago i was gona make these just as you sugested, went to the junk yard to get a whole buch only to now find out that any EATC before 93 only has 14 wires. 93+ new unit have 16. THAT HOW I GOT SCREWED UP. i KNEW i counted correctly! ******** IT, where were you 2 years ago drdave to point this out to me. headbang headbang headbang oh i feel so freak stupid right now. sadly poor GEN I guys will have to buy both 93+ EATC's and new units to upgrade.

<small>[ June 08, 2003, 02:51 AM: Message edited by: ohioshodude ]</small>

 

[drdave]

I demand a recount!

Seriously, I have units dated 90, 93, 94, 99, and 01. All units have two ribbon cables with 8 wires each. That's sixteen wires. The 90, 93, and 94 units have two additional wires for the light box. Those wires are in series with the original 16, so they're not needed for the mod.

If you do have sixteen wires, they wire straight up.

The chip you ask about has to be pre-93. I'll look at my 90 and let you know. It may have to do with units that had the green display.

Recount your wires and get back to me. Post a picture if it only has 14 wires. I have not seen any units like this. Also post the year of the unit/s in question.

<small>[ June 08, 2003, 03:03 AM: Message edited by: drdave ]</small>

 

[drdave]

You edited your post before I replied.

Maybe my 90 was upgraded before I purchased the car.

There are two solutions for people with pre-93 EATC units. First, someone can send me one and I will work out the details, or they can go to a junkyard and purchase 93+ units cheap that have broken buttons.

Damn, you’re going to make me change my post to “Yes, you can use (almost) ANY eatc!”

 

[ohioshodude]

yep all my pre 93 units have 14. here is a picture.


and just to show i'm not bs'ing you or anoyone else some of my eatc units. i have way too many.

 

[drdave]

WAY too many. Were you wanting to corner the Ebay market someday?

If it's important, it should be easy to figure out the 14 wire units. I can send you the pin-outs and you should be able to figure it out.

But you'd have to share the information!!! boink

 

[ohioshodude]

drdave:
WAY too many. Were you wanting to corner the Ebay market someday?

haha so true. actually i was gona use the EATC's to start my own company. was only gona charge what it cost me to buy and build them but at least i'd have started my own business. something i've always wanted to do. i'd love to have the pinouts and as i said i'd be glad to photoshop up a diagram so all sho members could have the info.

 

[Slo-Sho]

The units I have modified use the older, larger numerical display. It fills the faceplate quite nicely. It's good to see "pioneers" like you furthering themselves for the greater good.

BTW; Does anyone know if the outside temp sending unit has ANYTHING to do with the interior cabin temp control?

 

[autobahnsho]

ohioshodude:

and just to show i'm not bs'ing you or anyone else some of my eatc units. i have way too many.

YOU EATC WHORE!!!

If you fly one out to me I'll buy you an ice cream to eat while you watch me install it then you can drive the Plus on the Autobahn...

Please please figure out how I can do this w/ mine, so I don't have to get in t $$$ too deep...

&lt;---- drdave

<small>[ June 08, 2003, 02:55 PM: Message edited by: autobahnsho ]</small>

 

[drdave]

autobahnsho,

Get yourself an EATC with the buttons that you want, send it to me, and I'll send you a working unit.

 

[PuckHead]

So, my good Dr., do you schedule appointments for this transplant surgery, or are you just going to let us ***** it up ourselves?

Seriously, I would be interested in an 'exchange' for a upgraded one. How much do you think it'd cost? What timeframe do you think it would take? Possibly before the convention? wink

Please let me know, as my buttons are shot, and every time I look at it, I just get ******. cuss

All hail the good Dr.!!!!! hail hail hail hail

Later!
boink