Restoring MPH/KPH switch on JDM/Aus vehicles (WIP)

[kt45]

So soldering 2 smds is all that is needed? Anyone do this yet? Ill be definitely be looking into the STI cluster if someone is succesful at this.

[Futaba]

Originally Posted by kt45

So soldering 2 smds is all that is needed? Anyone do this yet? Ill be definitely be looking into the STI cluster if someone is succesful at this.

Will be doing it as soon as the SMD's arrive (ordered from aliexpress so could be here soon or weeks away

You would still need to either swap out the full 3 switch unit or modify the blanked button as per the guide to make it all work, but as far as electrical components go, it *should* just be adding the SMD components that are missing.

Hopefully I can give you a solid answer on that soon!

[socksy]

I have modified the switch 7 added resistors but when button pressed the display still shows km/hr. at bottom

[socksy]

I modified the switch & added resistors but display still shows km/Hr at bottom when switch pressed

[Futaba]

Originally Posted by socksy

I modified the switch & added resistors but display still shows km/Hr at bottom when switch pressed

Do you have a picture of the pcb after the 1k and 10k resistir was installed? We'll nees to dig deeper, if possible check continuity between the pin on the switch unit for km/h / mph and the pin on the dash unit linked to the installed resistors, if theres no continuity it'll be the eiring between switch cluster and dash, if there us continuity then we're likely goung to need to analyse our unit versus a switch enabled unit in closer detail

[socksy]

OK -I will check wire tomorrow. I didn't get picture of the PCB but I'm sure that it was OK. What about the other pads above the resistors that were added? Wouldn't the other switch inputs be the same?

[Futaba]

Originally Posted by socksy

OK -I will check wire tomorrow. I didn't get picture of the PCB but I'm sure that it was OK. What about the other pads above the resistors that were added? Wouldn't the other switch inputs be the same?

It's a possibility, however the layout I outline in the first post is taken from a unit that is known to work with the switch, so the resistor positioning *should* be right

If it isn't the wiring or somehow a non-working solder joint, then it may be disabled in the ECU itself, though I would like to think that it isn't that extreme.

[socksy]

I tested the wiring & all OK. Orange wire. Also checked switch operation & is good too.

[socksy]

Hi Futaba
Have you made any progress with this?

[FX86]

im in 'murica and i use km/h on my fr-s....because it makes my 0-60 times look faster

[socksy]

Has anyone managed to get this to work yet?

[Futaba]

Sat down with some spare clusters this evening and finally figured it all out, updated the original post with a complete guide to enabling this functionality on a cluster that does not normally support switching between MPH/KPH!

Enjoy!

[Luns]

Originally Posted by Futaba

Sat down with some spare clusters this evening and finally figured it all out, updated the original post with a complete guide to enabling this functionality on a cluster that does not normally support switching between MPH/KPH!

Enjoy!

Amazing job!

I'm in the US, so wouldn't need to do this mod. However, conversely, I don't have the rear fog light that's available in kph-only markets. I wish I could convince my US-market body ECU to properly support one.


Just one minor detail I spotted: in your photo of the switch PCB, there are diode symbols on the board that spell out their polarity. The individual Odometer and Display LED lines are switched grounds (cathode) while the one marked LED ground, according to the symbols, would be a positive voltage (anode).

I find this a little puzzling though; I would have expected this LED, where it's used, to dim along with the rest of the dash. However, that dimming is done by modulating a cathode shared by everything on a B-W wire, with positive voltage supplied via purple wire from a fuse off the taillight relay.

I'm inclined to side with the markings in the switch and guess that cars that have this illumination present, have a fixed brightness?

[Futaba]

Originally Posted by Luns

Amazing job!

I'm in the US, so wouldn't need to do this mod. However, conversely, I don't have the rear fog light that's available in kph-only markets. I wish I could convince my US-market body ECU to properly support one.


Just one minor detail I spotted: in your photo of the switch PCB, there are diode symbols on the board that spell out their polarity. The individual Odometer and Display LED lines are switched grounds (cathode) while the one marked LED ground, according to the symbols, would be a positive voltage (anode).

Right you are on the polarity of the switches, , would have caught that but never saw the point of installing the LED's as the buttons are solid with print, on every switch set I've seen.

With regards to the rear fog light, my Japanese GT86 also did not come with one (I believe it was not available at all in Japan on any model of the GT86 or BRZ.
But as a rear fog light was a legal requirement for the process of taking the vehicle with me and registering it for use on UK roads, I needed to have a working rear fog light.

What I found was that the loom in the boot that goes under the lower lip trim of the boot seal, has connection there, and the source side of the connector has an additional wire fitted to the connector that was unpinned on the connected section of loom.

So how I went about it was removing my center lower light cluster, drilling and notching the center cavity to match the left and right cavity openings, then sourced a bulb holder and wiring that matched the left and right, I ran the positive for this newly installed center bulb to the connector, adding the pin to the empty side of the connector, so that it uses the unassigned pin on the source side connector, then attached the other end of the bulbs wiring to ground, I then took apart my squib ring and swapped the right hand stalk (indicator/lights on the Japanese GT86) (with one from I think was an Australian vehicle in the end?) Which connected directly up to the stalks normal connector, which added a final switch state for that stalk (sprung so you twist against spring pressure and release to toggle it) and without any other modifications beyond the new stalk and adding the center light to the existing connector + ground, using the rear fog switch does as it is supposed to, and when your headlights are on, using it enables the rear fog light indicator on the dash, and turns on the center rear fog light.

I would imagine the same could be done with your vehicle without any additional steps, the key part is finding a indicator stalk for the correct side that has the rear fog light setting on it.