Got a 2005 F150 XL reg cab short bed, you get the idea, as base as it comes. Been on the project of up-specing it and one of those projects is adding EATC to replace the manual hvac controls.
I got all the wiring hooked up and everything seems to work just fine, even the steering wheel controls...but the AC clutch never engages..
My understanding after looking at all the diagrams is that on the manual controls, it uses pin 3 on the control head to send a signal to the cluster on pin 2 of the plug on the right, to request the AC clutch to engage.. But on the automatic CC, it doesnt have pin 3 populated at all on that larger 26 pin plug and as far as I can tell, it uses pin 12 on the new 18pin as "UBP" to send data signals to the cluster on pin 29 on the left plug at the cluster.
What I've done is just delete the connection from that pin 3 to pin 2 since it seems unused anyway, and then I tapped into that pin 29 and connected it to the pin 12 of the EATC 18pin.

My question here though is did I even do this right? I've followed the wiring diagrams as best as I can but it seems just nothing is working.
Could it be that other modules in the system need to have that option programmed in in order to accept and handle the new AC req signal?
Could it also be that I picked up a faulty EATC module as well?

I need some insight from the more knowledgeable out there

P.S. -- The sun load sensor that sits up on the dash..integrated with the PATS indicator(Flashing red light when car is off)..Are there variations of this module that do and dont have the sun load sensor in it? Mine had the pins on the module but the plug didnt have the wires..I went to a junk yard to find the plug with all the wires and I wired it all in but I dont know if theres a way to know if its working or not..other than probing it which i have yet to do.

 

Condolences?

To get the EATC to even remotely work right, you quite literally need to swap the complete dash and everything behind it. You will need little stuff like that interior air temp sensor that sits behind a little grill under the cluster that the EATC needs…

The HVAC for the EATC runs through the gauge cluster somehow. Guys who have swapped higher trim clusters from trucks that have EATC end up with non-functional AC themselves and they have to hack things up to get anything to work.

tl;dr - Just buy a truck with that AC system if that’s what you want.

 

this gets brought up here periodically. I’ve yet to see/hear about anyone completing (without some issues / non working functions).

regardless, what is the point/goal of attempting this mod?

 

End goal/ point is honestly because i want to and its how I learn to do the things I do..also like i said, my end goal with the truck entirely is to turn it into an XL with all the lariat features, cause why not, its fun. I bought this truck last year knowing almost nothing about cars in general, but now i feel like i know everything about my truck.

I have got it kind of sort of working, but the problem is that the A/C compressor is always running, as if the A/C button is on always, even with the whole EATC in off mode. Its a temporary solution until i figure out how to get it to work properly, but what i did was i left the connection from the 26pin plug to the right plug on the cluster with pin 3 and pin 2 respectively, the way the manual controls requests the A/C compressor, seems the EATC always outputs the signal it needs, whether that be a simple 12v signal or whatever(I dont know exactly what signal it is)

 

UPDATE:
The entire A/C system is working as expected(Except the Sun load sensor which isnt hooked up yet). I followed the diagrams exactly and I mentioned that the A/C compressor wasn't working at all...Fix for that, reprogram the cluster(yes, i know the issues that come with it)
I used ForScan to do this and used the as built data for the IC 720-01-01 as B6C2-0000-00A1. I pulled this from the motorcraftservice.com site using a VIN from a car I found at a junkyard I knew had the EATC

Issues that came with reprogramming the cluster are, in my opinion, not enough to kill the idea for me. Key functions that dont seem to work is really only the door ajar switches which also causes the dome/courtesy light to not work properly, but I'll address this later when I find a BSM to install since the switches are supposed to go through it and communicate to the cluster over the UBP comm line.
However, it does open up more upgrade paths, if you want to call it that, like the ambient air temp sensor, which now i just need to wire it to the cluster, and also the compass module.