Hi guys, so I need help from someone who has already installed the Jaycar Speedo Corrector. I have a 2001 bugeye wrx.

I am having trouble finding the wire to split into.

So I removed the gauge cluster, unplugged the 3 connectors and got out a multimeter. Got a ground source and got the positive/red ready in my hand. I put my car up on a hoist so all wheels off the ground. I put it in third gear and let out the clutch to get speed. And I did that for each wire in the middle/large green harness/connector. However I could not find a wire that would increase in voltage as I spun the wheels and dropped back down to around 0 V when the wheels have stopped. I could not find that characteristic in any of the wires. I'm sure someone on here has installed this before so i'd appreciate any help. Thanks.