Good stuff Redhill.... The wires you are trying to trace normally are routed down near the under or near the harmonic balancer along the lower chassis/frame and are possible covered with dirt or muck.

As far as parts its hard to say with out being right there with the truck and without testing instruments (I. E. multimeter) . Based on your symptoms seems you are on a good path.

97 Ford Ranger 2.3L 4 CYL... SIDE STEP BABY.... (road worthy.... Well almost) .