I have a 92 Dakota 4x4 5.2L V8 Magnum 120,000 miles with a snowplow.

Last summer it started stalling every now and then a month or two apart. Then it started stalling much more often. It would stall while stopping, accelerating, and cruising at 55 mph. The mechanic checked the codes and installed a new IAC. Probably not related, but he also installed a new muffler and exhaust pipe. The IAC seemed to help.

Now it only stalls when the truck is warm when I'm coming into a stop once every couple of weeks.

The stall is warning less; the engine just cuts out. When this happens starter will just barely crank and the truck doesn't start. After sitting a few minutes to a couple hours it will start right up with no problem. It's almost like the Auto Shutdown kicks in for some reason and won't let the truck start until cools down. I haven't been able to test anything while the truck is shutdown because it always has been happening in intersections on my way to work.

I scanned for codes after the last time and no codes came up.

Things I've looked at/tested:
Coil (primary coil checks out, I can't get a ohmmeter reading on the secondary coil. I'm probably connecting the wrong parts of the coil to my meter. Obviously the secondary coil isn't complete shot because the truck runs most of the time.)
Battery is new last summer
IAC is new one month ago
Distributor cap/rotor look okay. There is a oily film under the cam sensor.
Alternator passed a test (it should be working fine since the truck turns over just fine after a couple hours; the battery is charged.)
The splice looks like the previous owner repaired it.
Throttle Position Sensor passes a voltmeter test (some reving at constant throttle at low speeds 25 mph)
I just switched the ASD and Ignition relays for the AC and starter relays. There hasn't been enough time to see it that helps.

Any ideas?

Also, this may or may not be related.
The temperature gauge on the dash reads cold. It is two needles width inside the normal operating range. This started sometime near when the stalling started. I replaced the thermostat and the coolant temperature sensor passed a ohmmeter test at two different temperatures. Coolant seems to disappear somewhere. I haven't noticed a leak and the exhaust doesn't stink. Any thoughts?

My horn just quit working a month ago. I replaced the relay, but it didn't help. I haven't tested further because the stalling is far more important.

Also, there is a current draw when the truck is off of 80 milliamps. I did find a short in the snow plow main power line where it had been rubbing, but I fixed it. I've isolated it to the vehicle lamps circuit. Where would the most likely place of the draw be?

I enjoy doing things with my hands, but I don't have much experience/tools for working on cars.

 

Sounds like an electrical problem. There are several problem splices. Are you sure all are fixed? Are you sure they are done correctly?

 

I had all these weird problems on our 89,combined with no overdrive, no cruise control. CPU was losing ground where harness bolt secured pin connector. It did not show any codes. check that bolt for a good tight connection. If connector harness is not seating against the hold down bolt this may be your problem. I replaced ground cables and did the stuff you have. I would try a secondary ground to the mentioned bolt straight from the neg terminal of the battery. Sounds stupid but the truck has not skipped a beat since finding this, cruise works,od works and the little brat now averages 20 mpg ( 3.9 V-6) Just tonight the headlights refused to come on but the switch feels sloppy compared to our 94.Good luck on this one.

 

I'll check the grounds tonight.

One of my friends suggested it was the ignition coil. The theory was that it is failing and gets hot and cuts out. Does this sound reasonable for the stalling?

 

The factory coils were designed in a way to with stand heat and vibration.