VSS Vehicle Speed Sensor

I took a Temp / Compass in upper dash center console out of a 94 Blazer.
I have the wiring diagram for it. but what confuses me is that one of the wires if for the VSS.
Does anyone know why a Temp/compass would need that VSS hooked to it.

I have noticed that the temp works fine but the Compas is stuck in Calibrate mode. Maybe it is stuck on Calibrate mre becuse it needs the VSS hooked up.

So does anyone also know where this wire is and what coler code it is?

Thanks
Bobby