Ok so I've been doing this a long, long time. 35+ years or so, and every now and again I know 1 is going to come to that just slaps you in the face, takes your lunch money and goes home. This just your average Grand Caravan, 2004 3.3, grey seats, lol. So I've had an intermitent miss, put the boot in it and it clears up, it's my so I'll get to it when something changes. I put a reader on it, cyl 3 misfire, no big deal, I'll get to it. HA! Enter.......the twilight zone. I'm driving along, I reach down to put the power window down( I only mention that because that really is when it started, as soon as the window starts to go down the van starts missing bigtime and then just shuts off. No cough or burp or anything, just like the key got shut off. I coast into a lot and check a few things out, I can't do much here so I tow it back to the garage. The ASD fuse is blown, I replace it and it starts but only on about 3 or 4 cyls. I pull a plug and it is cracked, and another is, and they all are cracked, all 6. So I keep going and coil pack is bad, check pulses and no pulse on brn/orng, pcm is bad. So let me draw a straight line here, I start to put the power window down, it starts missing real bad, it quits running and it needs the ASD fuse, 6 plugs because all are cracked with 1 having a piece out of it, coilpac (yes it's fried too), and the PCM. What the hell? I have never, ever seen anything like this, or even close in my 35+ years. How does the entire system go all at once? I swear that if I wasn't driving I'd say it got hit by lightning because it's just that weird. Let me know if you have had this happen, I won't hold my breath, or if you have thoughts on this.

 

The first thing I'd check is the battery and how the alt is charging it. A bad cell in the battery could trick out the AVR in the PCM into overcharging it, causing the instant system-wide overload. Or it's also possible that the AVR inself went bad, with the same outcome. And it also follows that the window motor initiated the failure by triggering the system to increase charging.

 

I could be right on the money, out in left feild or somewhere in between. I think the plugs were installed by the previous owner, we bought it about a year ago and haven't put a ton of miles on it but it did get used alot, a bunch of short trips around town. Anyways, I think he managed some how to crack all 6 plugs when he put them in. That created a very high resistence in the ign system, or at least my brain says it should. With it being that high all the time eventualy pushed the pcm to far and the driver for #2, I think it was, didn't just stop working. I think it shorted out, I will know more hopefully when I rip apart this pcm but I might not see a thing because of the gel. I suspect I will be able to see it right through the gel. So when the driver shorts out and just before the fuse blows, the coil spikes to high and there it is, pcm + coil pac + asd fuse and I think all the power window switch did was just spike the voltage a tic at just the wrong time. I say that because the drivers side power window motors are notorious for going bad. I'd say the power window motor will be next. So to wrap up my thought, and please correct me if you guys think I'm wrong or maybe you know why because it's happened before, but I've never seen anything like it. Owner cracks all 6 plugs, resistence is through the roof, spikes the pcm ign driver which shorts out, and it takes the coil and the fuse with it all caused by a spike in voltage from power window.