weak spark

I got a 1988 comanche with a 93 4.0 h.o in it for a plow truck. the other day I was pushing back some snow banks and while getting ready so push another bank it started stuttering and just died. ive tried every thing i can think of. new coil new, ignition module,pick up coil, tps ,checked the cps,wired it direct(no plug),tried grounding the coil with a jumper wire but didn't help. it will spark real good for the first one then the second is a dull orange and then nothing.need help it's snowing now.

Best guess, ballast resistor, white box on the firewall somewhere.

I had a crank position sensor that tested right on specification (tested 200 Ohms on numerous occasions and temperatures) and didn't work. It was acting up for awhile (starts were getting longer and longer), before it finally crapped out all together. When it failed completely, it still tested good.
The only real way to test for spark, is to take a good plug and try it on each spark plug wire to ground. Watch the plug spark at the electrode.
I've replaced more than a few coil to cap plug wires. And have seen many caps that carbon arched or had excessive clearance and/or corrosion.
Try testing the 12 volt *in* (larger yellow wire) at the ignition control module, with it connected and back pinned. Watch the in voltage while your cranking. If it drops below 9 volts or so, it probably won't spark much. A combination of poor connections (resistance), old starter (uses excessive amps) and marginal battery will sometimes cause the ignition module not to receive enough voltage (amperage) to do the job. If your headlights dim much during starting, it's a sign the ignition system may be starved for juice.
Check the ground at the ignition control module for resistance and the module case to ground for resistance (ohms) and /or standing voltage. The ICM has more than one ground, but if they are both questionable, it will spark weak. If I remember correctly the ground for the ICM goes to a splice.