Sr20Det Speedo To Altezza Dials

[road runner]

Hi Lads,

I have an Altezza with an SR20DET from an S14. I am trying to get the original altezza dials to work with the S14 speed sensor but no joy.

Does anyone have any ideas what the problem could be?? I don't have the wiring diagrams for either which is a bad start but i'm struggling here big time!!

Any help or suggestions would be greatly appreciated. Thanks

[sparkystav]

ive replied to your thread on tezzaworld mate,

the wiring diagrams can be downloaded here, there for an IS200 but arent that different:

http://www.lexusownersclub.co.uk/forum/index.php?showtopic=80182

As for the wiring it should work mate as the wirings no different to the qualitat as far im aware. both are a 4 cylinder so the rpm signal should be fine.

[road runner]

Hi mate, the RPM is working fine its just the speedo that i cant get working. Any ideas on that one?? I'm not sure how the altezza one works either. Any help is appreciated, thanks again

[sparkystav]

the speed signal comes from the gearbox sensor

does the new gearbox have a sensor? will the standard one fit in?

[road runner]

Its the SR20 gearbox which has a speed sensor but i think it operates on 2 pulses as opposed to the altezza which uses 1 pulse. Im not 100% sure though.

Does the Altezza have a speed sensor mounted on the gearbox also??

Is that sensor normally wired straight back to the back of the speedo or does it go through the ECU and then an output from the ECU to the speedo??

[sparkystav]

yes its normally on the gearbox on the altezza, it actually goes through the speedo and then the ecu.

have you cut much wiring from the engine bay? check the sensor is still getting 12v

[road runner]

The Altezza VSS is out now and the SR20 VSS and box are in with engine running and driving perfect just the speedo catching me. Some of the Altezza loom still present but not on the VSS side.

Obviously there is a difference in the output from the SR VSS compared to the Tezza but i dont know what it is or how to check it.

[sparkystav]

You need the wiring for the Nissan then. I imagine it'll just be a pulse, but does it need power etc,

I imagine it'll need a 12v and earth, then the third will be the signal that goes direct to the speedo.

[road runner]

Thats what i was thinking but im not sure if its 1 pulse or 2 pulses and im trying to find the SR20DET wiring diagrams for the S14 but no luck so far.

[sparkystav]

I'm sure you could make a 2 pulse counting circuit to change the 2 pulses to one. Or just deal with the speedo being 2 as fast lol.

Is there any wiring left on the Nissan plug you could take an educated guess with? For example in the Lexus white with black stripe wires are earth, black with red stripe are 12v.