Today I did the Auto-shut Sunroof mod. I have always hated that the sunroof button has to be held down to shut the sunroof, and even more annoyed that it stops half way and forces you to re-push it. Not any more! Now with 2 quick clicks of the button, my sunroof auto-closes.
Sorry the file is so big. By the time I realized it was big, it was too dark to take a smaller one.
Anyway, Here is the write-up for this mod, which is really 2 mods in one.
First, the simple mod,
eliminating that annoying half-way stop. This one is super simple. Take the unit off the roof, and coming from the Moonroof control relay and switch (white thing in the below picture, there should be 6 wires (there are 2 versions of this control, this is for the newer version, I think '99+, though the previous years should be similar).
While I do have an FMU, this control relay came out of my original roof unit. So all you have to do is cut the wire to the limit switch, in my case, it was the yellow wire coming out of the control relay. I found the right wire by looking at the connector that plugs into the motor itself, which had 5 wires whose colors matched the FSM schematic shown here
I found the red wire, followed it to the Control relay end, and snipped it there because I had more room to patch it later should the need arise. EDIT: You should ground the side of the wire that connects to the control unit; this will prevent hesitation of the window when opening (described below).
Clip that wire, and you are done. You now just have to hold the button down, and it will go all the way in. You will hear it click as it passes the 100mm point, but it keeps going and automatically stops at the end just like normal.
Now, onto the auto-close mechanism. I borrowed the basics from a guy in the 4th gen section that did a good write-up, so instead of bogarting his work, I'll link to it and skip that part of the write-up. He does it for the rear window, but the principal is the same for the sunroof.
http://www.toyota-4runner.org/4th-gen-t4rs/85203-back-window-up-hack-factory-key-fob.html
So where I departed from that is that I didn't add a limit switch, so I can trigger the auto close anytime. I used a PAC TR7 and a 12V 40A relay just like he did, and spliced the trigger wire into the motor power wire (pin 2/4, light blue above, light blue because that is the high side when closing). The big difference is in the relay bypass wire. If you open up the control relay and look at the board, you find that the open and close buttons are just normally open switches that close to ground, so to keep all the stock functionality, I want the relay to act like this switch. Now that means bypassing the switch only and leaving the rest of the logic in tact. This is the tough part because it means soldering directly to the board. I found that the close-button switch connects to a via, then to R3 in the pic below.
The red arrow shows the trace from the other side of the board.
The VIA is too small to solder a wire to, so the only option is to solder directly to the side of R3. This isn't the best way to do this, but there is enough joint there that it is doable. I was hoping this node would have a test point (in fact, the open switch does have a test point) because they are big enough to solder to, but alas, it didn't. The test point between R3 and R4 is on another node, I know because I tried. Solder the smallest wire you can possibly find (and preferably solid core wire) to this resistor as I did.
WARNING: I don't recommend trying this solder job unless you have a good soldering iron (not a $20 radio shack special, a real soldering station) and some soldering experience. It is really easy to ruin components by letting them get too hot, and unless you have a good iron and experience, you run a big risk of frying that resistor or creating a very poor solder joint that will fail later.
You then have to modify the control relay cover a little bit to allow the wire to exit. I just used a knife and cut a small notch that worked fine.
Run the wire out, and connect it to the high side terminal on the relay, and you are done. You can tuck the relay and TR7 up in the roof on the pass side, then shove the giant rat's nest of wires in there and reattach your roof unit.
That's it. I noticed that after all this, when I hit the open button, it flinches, then stops, and I have to hit it again to get the sunroof to open. I suspect this is due to clipping the wire for the limit switch, but I am not sure exactly why it does this. I am going to try tying the yellow wire I clipped to GND and see if it fixes it. I will do that another day as it is dark now.
I am still thinking about the triggers on the rear window auto-shut circuit, so I haven't finished that yet.
