Mine is a 94.
The 5 volt wire is violet with a white tracer
The Signal wire is orange with a dark blue tracer
The Ground wire is black with a light blue tracer
At idle position, the signal wire should read about 1 volt (mine reads 0. 8 volt)
As the throttle is advanced, the signal voltage will increase and should be between 4 & 5 volts at full throttle.
I don't think the 94 cabling is as prone to noise (induced voltage) problems as the later models. In this truck, the 5 volt wire is dedicated to the TPS only while in later years they use it for the engine speed and vehicle speed sensors as well.
If you do suspect a noise problem the best way to eliminate that is to do, like shendren did, and cut loose the 5 volt and signal wires and replace them with a shielded pair.
Also, make sure the grounding is good.
You will find it in a group of several black wires with white tracers combined at a large bolt at the front of the engine on the driver's side next to #1 cylinder.