Early Dakota had a problem with the power wire from the ignition switch breaking off one of the 4 or 5 wires from the splice. That splice is located in the underhood harness where it makes the turn around the brake booster. (I forget which side of the brake booster its on, but I believe its the engine side.) The splice in question is pink wires with a blue tracer (or blue with pink tracer). It comes from the ignition switch and splices the power for the crank sensor, the throttle position sensor, the dist pickup, and the coil (and something else). When you locate the splice in the harness, the splice will have that green battery cable look to it. there are 3 wires on one end and 3 or 4 wires on the other end. You may have to untape the splice. One or more of the wires is probably broken off at the terminal splice.
I've seen this on 3-4 Dakota trucks. It often bites when you try to start it, but I've seen it shut down running trucks. Crank all day long, no spark, no codes, no voltage to one or more of the engine monitoring systems. The computer won't pick anything up because as far as its concerned, your not doing anything to the truck.

Just for your info, often the rest of the wiring harness looks great, except that one splice. Gene