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In the engine bay its on the computer's 104-wire connector, pin 68, this is the Source of the VSS signal, it runs to cruise, cluster, and GEM
If you have Cruise Control its on pin 3 on the module in engine bay
In the Cab its on the back of the instrument cluster, C220B pin 1
Also on GEM module C2100A pin 14
At all connections its a Grey/Black stripe wire
These wires have Ford's standard 8,000ppm(pulse per mile) AC signal
Its just 1 wire, vehicle's Ground is the "other wire" needed for the circuit