Yep, they won't function at all unless you re-wire the physical buttons to another board like I'm doing.

And since it's on my mind, I need to figure out what I'll be doing about the LEDs. Maybe try and remove the tiny lights from the metra board and relocate them with more wires to the chopped OEM board? It's not a huge concern since all the climate information from the lights is also displayed on the in-dash climate display, but I really want it to look as good as the JDM trim replacement.

 

Morning update:

I mapped out how the internal wiring between the factory buttons goes (any resistors they go through so the computer can figure out which button was pressed is not shown):

*IMAGE REMOVED, SINCE IT MAY NOT BE COMPLETE*

Since some buttons share both sides with others, I'll have to physically rotate some of the buttons so that they have no soldered connection to the internal wiring in the board.

I'm a little worried about the height of the button changing due to the glue, but I'm pretty sure super glue will hold it properly without changing the mounting height, so the buttons will still feel and operate just like an unmodified board.

 

Good luck^

 

Another quick update:

No rotation necessary, I was able to use a small file to just break the internal connections by scratching at the surface.

Further update:

It's ready for testing. Also, there *may* be a couple more internal connections I missed on that image, or it may be down to one sloppily-soldered connection on the Metra board from like a month or so ago when I started.

 

Video of the first test! It's sorta-working, buttons are sending commands, but it looks like they're getting overridden by a short. That or it's *really* complicated. I was really hoping to call this complete this weekend.

 

Yeah... Having it work perfectly the first time out would be too much to ask!

 

I'm regretting now that I never tested it before any modifications were started, just so I wouldn't have those doubts, since the guy who sent it to me got it used.

 

Alright, pretty sure I've got it figured out now.

In addition to the direct connection between them that was easily identified earlier, there's the wiring through the resistors on the OEM board. I guess there's going to be more breaking contacts on the OEM board like before.

I think the solution for this will be to just run a very thin drill bit or file in each of the tiny circles on the OEM board. There's a lot of them, but it only takes a few seconds to scrape each one clean of electrical contact, and identifying the ones that are actually need to have the connection broken end up taking longer.

 

that seems soooooooooo complicated. Very impressive skills.

 

+1 on your skills, can't wait to see it done

 

I've done pretty much everything I can think of to try and separate the buttons on the OEM board. Lots of ripping tiny resistors, transistors and scraping board wiring off. As far as I can tell, there's zero connections left on the OEM board, so it *should* be good. I was hoping to get a response from somebody with a Metra board to check resistance on it to what I'm seeing on this one. At this point, I'm thinking that rather than hacking up the OEM board, it might be easier to get a blank electronics project board (like this) and move the buttons to that to avoid having to break all those connections in the first place. It would require some fairly accurate placement of the buttons, but you've got a few millimeters of wiggle room for the black OEM trim buttons to hit the electronic buttons, so it's not as bad as it sounds.

I hate that it's taken this long, but luckily the owner of the Metra board hasn't put any time pressure on me, so I'm able to do it as the hobby, rather that seeing it as a job. Still, I was really hoping that the test a couple weeks ago would have worked so I could move on to doing up the plans for laser-cutting the OEM trim and some cheap ABS plastic to pair up to make a nice DDin opening.

 

And test #2.

It works.


Since the recirculate/fresh air lights and the rear defroster lights aren't mirrored at all in the in-dash display, running those lights should be done.

So, big lessons learned:

1) Use a prototype board instead of the OEM board, it's just too much frustration eliminating all the connections on the OEM board. Removing the buttons only takes a few seconds once your soldering iron is warmed up.
2) I still want a better method for the temperature, but the mounted buttons inside work.
3) I absolutely do not recommend this method be used so long as the JDM climate controls can be acquired.
4) 40-pin IDE ATA/33 hard drive cable works pretty well for this job. Don't try ATA/66.

 

Stunning work Wrathernaut!!! Your patience and persistence are just unreal !!!

 

do you actually have to take the car apart every time you test this thing?

 

Yep. I have gotten pretty good at it though. 5 minutes to get the radio out at this point. A bit longer to put it back together, since I've got to double check connections and make sure nothing gets scratched.

I only had to test this twice though. Since it's apart now, I am going to pull the tablet out and connect a 3.5mm jack to it so it will connect to the radio via aux instead of over Bluetooth. The radio I've got can only auto connect to a single streaming source, and I still want it to connect to my phone as the default.