R33 Kmh To Mph Converter Problem

[ncno]

Hi,

Seeing this is my first post, I better say it's great to be here. Sorry my first post is regarding a problem.

I've recently been taking my interior more or less apart. Doing this, I found a KMH to MPH converter connected behind my cluster. This is what it looks like disconnected.

Clearly it is AFM. Probably installed by the guy who had the car before me.

I took it out due to two reasons.

1. I would like it in km/h if possible.

2. I didn't like the quality of the install.

The green and red wire goes directly onto the cluster - Two screws securing it. They are located around the back of the speedometer.

The blue wire goes from the black PIN-connector (Upper row, 2nd from middle). Original wire is grey with 2 red lines.

Yellow wire goes from the bundle of cables which is behind the cluster. Also grey with 2 red lines.

The converter says as follows:

Red: 12v

Green: Earth

Yellow: KMH signal input

Blue: MPH signal output

I am not a 100% sure the yellow wire goes from the bundle and the blue from the PIN. Perhaps it's the other way around. If necessary, I will naturally make sure as soon as I am at the car (it's parked in a garage for the winther).

I've had a voltmeter onto where the yellow cable was connected - With the engine running it occasionally gave a small reading. Note: It was only in idle.

Is it possible to just connect the 4 wires (2 from the car, 2 from the speedo-cluster) to get a KMH signal, or should I just reinstall the converter? Furthermore, how should the 4 wires be connected to one another?

Car spec:

Skyline R33 GTST S2

Haven't been able to find any answer. I hope I'm not asking a stupid question. Any help is much appreciated.