Stereo & Electronics - Aftermarket speedo question

i was wondering if any of you guys can help me answer this?

i bought a set of aftermarket gauges and the speedo has 1 signal wire but looking at my cars wiring diagram it looks like the wires come from the gauge cluster and then to the speed sensor then back into the cluster.

how would i hook this up?

heres the cars diagram:

http://i131.photobucket.com/albums/p298/90SupraMike/Vette/101_4992.jpg

heres the gauges diagram:

http://i131.photobucket.com/albums/p298/90SupraMike/Vette/PICT6250.jpg

I can look on my vantage tomorrow at work and get back to you on this. It will tell me what each wire on your speed sensor is for. I imagine one of the wires coming from the cluster is (+12v) or (-). The other would be your signal wire.

i remover all the old wiring and the ECM thats the only reason why im running into this issue.

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this is what one of the guys from corvetteforums said

In the early C4s the digital cluster gets the VSS signal first. The cluster then clips the signal and sends it to ECM. The VSS signal from the output housing of the transmission. generates creates a AC voltage. Output ranges with speed from 5 volts (VACRMS) to 80 volts (28.8 VACRMS) peak to peak. This signal is a typical AC sign wave....no square wave until it hits the components in the cluster where the signal is chopped or clipped for the ECM and speedometer/odometer @ 2,002 pulses per mile traveled.Your after gauge you have choosen doesn't appear to have this clipped signal option. Some after market gauges have this option but they run $200+ just for the speedo. The problem with hooking up an non clipped speedo is that the ECM will not be able to adjust as the car speed changes and the car will not run/idle properly most of the time.
Here is an example of a speedo that will work:http://www.autometer.com/cat_gaugede...id=3749&sid=68
Instruction for the above gauge:
http://www.autometer.com/productPDF/1268.pdf


heres some more info (if you go down to page 4 it shows you)

http://www.jagsthatrun.com/V8-chapte...ed-Sensors.pdf

http://www.socalmuscle.com/forums/imagehosting/thum_2749a6701f7cae4.jpg