It is sometimes bit cold in here, and steering wheel stays unpleasantly cold for a while, so I would love to retrofit a heating (strip the wheel, put some pads or nichrome and rewrap it with fresh leather)
But the obvious problem is supplying power to the heaters. I wonder if I can use shift up/down wires, since GS430 is missing those buttons anyway. I guess it should be fine to pump some high voltage/low current power through them. But I also suspect they can be sitting on the digital bus, so...
Could you please help me with clock spring (spring wire) assembly pinout? I was unable to find one
Some random google result on “clock spring pinout” search did bring out some interesting information
From what I see it is very possible to install “wrong” clock spring assembly and use two extra pins for the heating. I can accommodate for pinout change on the steering wheel itself, and also replace the airbag plug on the new clock spring
I still wonder if the “car side” of the spring is much different?
Since it all looks pretty promising- the spare steering wheel is ordered.
As a next step it going to have a little trip to Ukraine for carbon fiber based 30v heaters installation with re-wrapping. It going to take a little while but I’ll keep this thread updated
A little update on the project that is still alive. And moving.. slowly
Right after the new steering wheel was done with it's beauty treatment and was shipped back to Germany, after new clock spring was finally found for not the whole money in the world, and also got on it's way to the destination- extremely smart Mister Me decided to finally do what had to be done at the very freaking beginning... To strip the steering column and make sure that the clock spring in the car is indeed 4-pin. And what a surprise
Liiiieees!! I was feeed with filthy liiiess
Got really disappointed for a moment, was thinking about how hard would it be to modify the clock spring and add another thin flex cable to it.
Also was almost feeling that random airbag blowout into my face, when 30V flex cable manages to grind through the isolation of the tasty SRS tracks
I felt confused about so many pins and finally managed to get a full pinout, piece by piece, with help of two service manuals (electrical repair manual and electrical wiring diagram)
Here it is (valid for GS430 with Cruise Control and Multimedia Pad on the side)
Shifts are for GS300 they use same pins, that in my case are taken by multimedia controls (B+ and MPX)
The absolute best thing - is pin number 3. That big phone pick-up button is apparently connected directly through the separate wire, and not something fancy and digital (kinda make sense, since it's controlling different electronic block).
Anyways- it's 2024 and not a single person in the world gonna ever need it again, so I am more than happy to hijack it's wire for +30V
Horn uses ground from steering wheel itself, so I am expecting it to have some proper electrical connection to the chassis.
As a bonus I can return the questionable clock spring and get some money back to spend on Aliexpress connectors
In the next episode:
-You'll see the brand-new-like steering wheel (it really does look nice, can't wait to see it fully assembled). Gonna get my hand on it next week.
-Some breakthrough schematics will be unveiled and built. Waiting on tiny latching JST GH connectors to make everything fancy and serviceable
-Mindblowing industry intended DC-DC step-up regulator show-off. Still have to decide on exact model and wait for a delivery
Just a little follow-up on the last post
I have experimentally confirmed (by unpinning the guy #3) that no important functionality is affected
Horn works, multimedia stuff works (fully: mode, next, prev and vol+, vol-, vol set).
So it's really only this big guy, that is now completely unemployed:
What a pity (nope). Excuse the dusty mess, I really need to take care of that
But I have experienced some troubles while testing ground continuity on the steering wheel aluminum core, that is crucial for my plan. I got some crazy readings all over the place around 1k.
I'll be digging deeper into that during the steering wheel replacement (there'll be some better access), but I will appreciate any input on that matter
Plan B could be using an isolated DC-DC regulator and use B+ as one of it's points, but that is kinda complicated and pretty expensive
By the way it helped me to realize, that Cruise ECC pin is actually connected directly to the ground.
I just needed to pay closer attention to the wiring diagram, who could've guessed, right?
Yeah, this is the write up I’ll be following, but there’s no pics of where the clock spring is accessed or the diagram. Though I have the wiring book from Lexus it’s nice to see a photo of where I can get into it.
Last day of winter felt just right to install everything
Here is the schematic I have made. It show all the components added to the car wiring.
Steering heating is enabled together with drivers seat heating. I find it kinda pointless to have a separate button, that also need a cut-out, and would look off. Stealthy is the way
I kept the original fuse (i feel like 20 already has a loooot of headroom), but if it ever pops- 25 amps will hop right in. I am also pretty sure the stock wiring can keep up just fine.
I also have managed to pull out the trick without cutting a single wire in factory wiring that makes it kinda bolt-on solution.
It’s not like it matters, but I really really hate messing the original wiring.
That’s achieved by a little “adapter” that connects between seat heating switch and its corresponding plug. It lets all the signals through as usual, but also outputs the drivers heater supply to the separate connector.
It does that with two pairs of wires since we’re getting a little close to connectors rated current- more on them later.
From there it goes straight to our DC-DC Step-Up regulator (it’s 7 pin main connector), and its output is supplying the steering heater through pin 3.
The hardest part of a “bolt-on” was identifying the type of connector that media controller is using (it looked more generic, than main connector of clock-spring, so felt like it should definitely be available for cheap)
Spent a whole night searching, scrolling, no luck, gave up. Cutting it is. Day after - found it by pure accident on JST web-site while trying to find a proper connectors for all the other electrical connections: JST GH plan failed miserably, since normal female connectors do not exist. Only SMD board headers that are totally unusable in our case.
Anyway, JST XA it is and we can now build the same “adapter” to terminate and bring out the pin 3 inside the wheel, together with a GND.
XA will also do perfectly fine for all the rest of our connections: it has a latch, it’s pretty compact and has adequate current rating. It is still lacking normal female version, but the through-hole board header has thick and strong outs that can hold wires perfectly fine.
Last but not least- inputing the high voltage heating supply is done by unpinning original phone wire (cutting is strictly agains my religion, as you might’ve noticed already), and putting in our new line with it’s own pin.
By pure luck I had some spare mirror wiring laying around, and small pins from their connectors are exact what’s needed in here.
The dream-team:
Voltage regulator is MEAN WELL DDR-30G-24. It is designed for DIN-Rail, so it has nice enclosure. Rated for 24V but can be adjusted up to 28. Rated output current is 1.25 amp which is more than enough (wheel consumes 0.8). Featuring all kinds of protection, and temperature range is pretty impressive- designed to work in environments as cold as -40C.
And the best thing- is that it’s not a no-name chinese crapy board, so it has much less chance of burning my car to the ground
The 4A fuse was added by me.
I have made it an aluminium mount (with piece of din-rail epoxied) that screws to the brake cylinder bolts, and situates it right next to VSC ECU. Other option was right in front of the AT Selector (there is an almost perfect "pocket" for it), but I felt extremely uncomfortable producing some electrical noise right next to the SRS ECU. Air convection would also be extremely bad in there (supply still needs at least some cooling).
Transferred all the stuff from the old to new steering wheel, secured new wiring with a tape:
Put all the new wiring in place:
Here is something similar to a clock-spring, but for the telescope. Basically- just a loop of wires.
And voila:
One nice and warm, fresh and gorgeous steering wheel (plus one very happy GS guy)
Color has matched super nicely, it heats up very quickly. I also asked to add a bit of a soft-padding, so it got a tiny bit thicker (some may not like it), but it feels so much better, and still looks like it was always like that.
You crazy bastard that is absolutely magnificent! I'm not smart enough with electrical diagrams to replicate that but if you ever wanted to start making and selling kits I would totally buy one.
if you ever wanted to start making and selling kits I would totally buy one.
I am guessing not much people would want it without modified steering wheel itself, and sourcing and modifying it is a big pain in the bum.
But anyone is welcome to hit me up regarding sourcing the components or whatnot, I still have some stuff in stock.
