Need a picture of a RB25DET speedo sensor

[Bishopsrock]

Thanks for that - I am confused about the sensor because there are two wires coming off it and I had thought that the sensor might need power?

 

My cable-x has now arrived which will take the speed signal and convert it to a cable to drive the original stock speedo - problem is that I cant find a wiring diagram to show how the speed sensor works so I am unsure how to connect it to the cable-x?

 

Do you know if both wires coming out of the speed sensor carry the same signal? or is one for another purpose/input?

 

Cheers

[Careless]

Thanks for that - I am confused about the sensor because there are two wires coming off it and I had thought that the sensor might need power?

 

My cable-x has now arrived which will take the speed signal and convert it to a cable to drive the original stock speedo - problem is that I cant find a wiring diagram to show how the speed sensor works so I am unsure how to connect it to the cable-x?

 

Do you know if both wires coming out of the speed sensor carry the same signal? or is one for another purpose/input?

 

Cheers

 

It should be a magnetic sensor of some sort. with 1-4 small magnets that are stationary within the unit, and one attached to a shaft that rotates passed the 4 magnets to produce a saw-wave. the shorter the saw intervals, the faster the unit is spinning.

 

I'm not sure if it's polarized but I don't think it is.

[getoffmyinternet]

When the cap broke off of mine, I saw that it was a magnet on a shaft, and the plastic cap over it it had a bunch of individual leads surrounding the magnet to generate a charge. I'm pretty sure one of the wires goes to the ecu (53?: At the ecu it is a different color), the other is ground.

[Careless]

My father has an electronics book from the 80's that displays how to make an electronic tachometer that is a bunch of magnets epoxied to the drive shaft with a reluctor magnet to sense rotation speed.

 

So i figured making it smaller and fitting it into a housing like that of the speedo adapter is what they would end up doing.

 

 

LOL @ your avatar and user title.

[Bishopsrock]

When the cap broke off of mine, I saw that it was a magnet on a shaft, and the plastic cap over it it had a bunch of individual leads surrounding the magnet to generate a charge. I'm pretty sure one of the wires goes to the ecu (53?: At the ecu it is a different color), the other is ground.

 

Thanks for helping,

 

So we are saying that there are 2 wires coming off the RB25 tranny speed sensor.

 

Which on my R33 JDM loom become coloured:-

 

1 - Grey with Red Stripe

2 - Yellow with Brown Stripe

 

One of these connects to the back of the GTR speedo and the signal is processed/modified by the speedo. It then comes out of the speedo from a seperate output and from there goes to pin 53 on the R33 ECU. This is the signal that allows the ECU to implement the top speed cut and so if we have used the Skyline instruments we might not want to connect the speed wire to the ECU .

 

The other wire coming off the speed sensor goes to earth.

 

OK, a couple more questions - which of the two wires goes to earth? or does it not matter which one is earthed? and have you any idea why they chose to take earth by a second wire when they could have just connected it internally to the tranny case? or have they already done that and these two wires are both signal wires running to different places - HICAS etc?

 

Cheers

[getoffmyinternet]

The ground wire probably goes into the loom to a common ground that is shared by many other components. The trail goes cold at the dash where the Y/G wire ends. I suppose if someone had the skyline gauges they could take a peek at the plug to find out exactly the color of the wire that goes to the trans.

 

[Mike Rowe]

My apologies, I have just seen and read this whole thread after already posting a new Thread on whether the RB20 mechanical drive will fit into the RB25 gearbox. However the question I have raised regarding the RB20 mechanical sensor hasnt been covered - does anyone know whether it will fit into the RB25 gearbox?

 

Second question some have mentioned in this thread that the R32 RB26 speedo gearbox drive is mechanical - has anyone tried interchanging this successfully into the RB25 gearbox? I want to maintain the use of the Z speedo.

[getoffmyinternet]

In case anyone was thinking of trying my mechanical solution, I have an update.

 

The pot metal weld stuff didn't work too well for me. It might work for an expert, but I was having a hard time getting it to soak in the rod. However, I was able to just straight up epoxy it together and it seemed to work fine...I went over a gnarly speed bump the other day at like 2mph and, albeit my suspension has yet to be updated or stiffened since the 26 swap, it got a little rough and the trans hit the post just right to break off not the end of the sender itself, but the cap from the cable.

 

Rather than by a new cable and hope for the best, I'm going to get a z32 (confirm that any manual will work?) sender and get rid of the cable all together. Of course that means I'll need a non-stock gauge of some sort (I'm exploring options) but the speedo didn't read properly anyhow. It was reading 20% low on the r180 (perhaps a different cog would have helped, but probably not enough, plus I'm getting the r200 soon.).

 

If you're moving the post anyway, I suppose this wouldn't apply, however you'll still have to go to a shop and have a calibrated adapter box or something put in to get it to work with the stock gauge after your whole drivetrain is set in stone.

[Ed260Z]

My cable-x has now arrived which will take the speed signal and convert it to a cable to drive the original stock speedo - problem is that I cant find a wiring diagram to show how the speed sensor works so I am unsure how to connect it to the cable-x?

 

Was looking through the posts again, and I wanted to know how the Cable-X worked out for you? When I saw this a few years ago I thought it would be a good idea.